I'm not a Little Snitch or Open Snitch user, I wonder if these firewalls are able to block requests done with the use of some other, allow-listed program.
Say I run a script `suspicious.py' and I deny this script from making any network requests. I also have firefox which is allowed to make any HTTPS requests. If suspicious.py does something like:
It depends. Little Snitch for Linux has a two level namespace for processes. It takes the process doing the connection and its parent process into account when evaluating rules.
Also: If an interpreter is run via `#!/bin/interpreter` in the script binary, it makes the rule for the script file path, not the interpreter. This does not work when running the script as `interpreter script`, though.
This gets even more involved when you consider things like loading libraries, there's also the impact of calls like OpenProcess/WriteProcessMemory/CreateRemoteThread (Windows-land versions, though I'm sure similar exists elsewhere).
The "good" Windows firewalls like Outpost and Zone Alarm used to have features to catch this, they'd detect when a process tried to invoke or open a running process which had internet access. They'd also do things like detect when a process tried to write a startup item. This went by names like "Leak Control" but it was basically providing near-complete HIDS features with local control.
With the literal rules described it would not be blocked. A more detailed rule (in Open Snitch at least, not as familiar with the other variants) could match e.g. whether the process's parent tree contained the python binary rather than just if python is the process binding the socket.
Not necessarily (with Open Snitch at least), it just depends how complex you want to make your firewall rules and what the specific goal is (block this specific script, block scripts which try to do this activity, block connection to evil.net, block python scripts, etc).
The more granular one gets the more likely they aren't really meaning to ask how to do it in the firewall layer though. E.g. if we take it further to wanting to prevent python -c "specific logic" it's clearer what you can do in the firewall is not necessarily the same as what's practical or useful.
The allow rule for Firefox is what would suppress the prompt. You probably don't want to have a prompt for every Firefox connection though, so you'd need to come up with some kind of ruleset (or get very annoyed :D).
The SELinux MAC policy should restrict which files and ports each process may access. In general, most modern distro have this feature, but normal users do not go through the rules training and default enable flag setup. =3
Sorry, we have not tested on Fedora before release. Did not expect so much interest in the first hours after release...
I have now installed Fedora in a VM (ARM64 architecture, though) and it does load, but cannot identify processes. I'm investigating this now.
The other issue seems to be with eBPF compatibility. That's a moving target and I'll investigate next. But resources are limited, I'll need some time to dig into this.
There's some good feedback in the GitHub issue on the subject, seems to happen on slightly newer versions of the kernel than the one you've tested on and affects other distros like Arch as well. I'll keep an eye on the discussion and test again once updates are ready.
"Note: Little Snitch version 1.0.0 does not currently work with the Btrfs file system! Btrfs is used by default on Fedora, so Little Snitch does not currently identify processes on Fedora. We are working on an 1.0.1 release to fix the issue as soon as possible!"
Yeah, because no third party program has ever crashed on any other OS.
Come on, this is an absurd comment. Linux has its issues, this is not a serious example of what is keeping normal people from using Linux as a desktop OS. Normal people are not installing the first release of a privacy networking tool that requires you to OK connections.
99,9% of the time, you download an exe or a DMG, you can be pretty sure it's going to work. Even 3 star github repo.
Only on Linux you get weird bug, compilation issues, etc.
After all, you have windows, macos and then you have Linux : debian, Ubuntu, fedora, arch, opensuse. That's almost like 5 different os just for Linux.
Sure you can use flatpack and force people to download 2gb installation for something that requires 20mb on windows and macos. That excludes all of the people who don't have fiber internet.
At this point I'm convinced that those developing Linux don't want it to be an os for casuals and prefer to stay in their small, niche community. That's fine by me but it makes claim of Linux desktop year laughable, which I was referring to.
The take on flatpaks is such an uninformed one. DMGs on MacOS come with all the dependencies bundled in, which make them essentially just as big as the comparable flatpak (minus the shared runtime that gets installed once)
Seriously, the amount flatpak misinformation that people hold onto is absolutely wild. Ex: I have had to show people it does differential updates because they don't bother to read the output.
Flatpaks are easily the best gui desktop app experience for users we have today.
That's not the user experience though, the user experience is it says "go to the discover app and install <program>" and they do that and it just works. Downloading a tarball is not the normal way to install stuff on Linux, and given everyone has phones where the standard is "install on the app store", it's hardly some new experience, in fact, it's more natural for normal users.
Recently I was wondering how viable it is to launch a niche, paid tool for Linux. I found that this is a very rare model, most tools are either just free, supported by sponsorship, supported by some paid cloud-based service that accompanies the tool, use an open-core model with paid add-ons.
I wonder if the decision of Little Snitch to make the Linux version free forever was also informed by this "no way to make money selling tools on Linux" wisdom or if there was another motivation. It seems that if any tool has chances of making decent money on Linux, a product like Little Snitch, which is already well established, with working payment infrastructure would be a good candidate.
Many from linux crowd are slightly paranoid and ideological.
I'm as a linux user very reluctant to install anything proprietary that has such sensitive info as my network traffic and would rather use opensnitch or any other foss fork.
The same time I don't mind to pay for open-source, I donate several thousands USD per year to FOSS projects. But I guess I'm in a minority here and if you make the whole stack open-source you're not going to make many sells really.
You call it paranoia, I call it zero tolerance for enshitification.
It's like the Nazi bar problem. You need to be vigilant to prevent the thing you rely on becoming yet another platform for Microsoft to exfil your personal data to NSA servers.
As the author of Little Snitch for Linux, I can tell you what drives us: we are a small company where people (not investors) make the decisions. It was a personal choice of mine, driven by a gut feeling. I'm curious about the outcome...
As a paying customer, I wasn't expecting this so thank you! Can you expand more on your gut feeling? Also, I have different security expectations on Linux vs MacOS. Would you ever consider open sourcing the daemon?
i have been pretty happy with opensnitch. ui improvements are always welcome although what might be really interesting would be some sort of plug-in system that allows for an agent to watch my interactions activity and the outbound connections and only flag things that seem surprising. also maybe some kind of improvement over the pop-up (maybe get rid of them entirely and add some kind of cli wrapper that allow-lists child processes).
I remember before Little Snitch there was ZoneAlarm for Windows[0] (here is a good screenshot[1]). No clue if the current version of ZoneAlarm does anything like that (have not used it in 2 decades). I always found it weird that Linux never really had anything like it.
If I remember correctly, it runs as a commodity and patches the socket library. Interestingly, the socket library was not re-entrant (unusual for Amiga libraries) so I had to patch the Exec OpenLibrary() function to monitor the loading of new copies of the socket library. But it's been a long time so memories are hazy.
It'll be interesting to see if it is still compiles and runs for modern AmigaOS, if any active Amiga programmers are around to see.
What I really liked about ZoneAlarm wasn't just that it was a very nice technology - and it was; but also that it got the user expectations and training right from a very early stage.
It was quite insistent on the fact that it would be "noisy" at first as it queried all the programs you ran, but would then quieten down once it had been "trained". It got that across in clear, simple language.
I think it was so successful because it got the soft side of its security job right as well as the hard part. It's certainly why I recommended it to anyone at the time...
Was working as an IT consultant. We got a call from an international manufacturer in the area for support. Local lead IT manager took down the firewall which infected their computer network around the world. All they wanted were bodies to help clean systems and apply OS updates.
My personal computer had ZoneAlarm on it. It became ground zero for reporting about infected systems. They ignored systems they thought were save; CISCO phone system running on Windows server and other backend devices. The company then bought a few licenses to run their own laptops.
It is such a same that Microsoft destroyed _ERD Commander_ and other quality tools which assisted in the clean up.
Run OpenSnitch for a while and you'll quickly realize how much of your system does phone home. Off the top of my head:
- GNOME Shell (extension updates without a way to disable this, weather),
- GNOME Calculator (currency exchange rates),
- NetworkManager (periodic hotspot portal checks in most configurations),
- GDB (debuginfod enabled by default),
- Firefox (extension updates, push notifications, feature flags, telemetry, ..., some parts cannot be disabled),
- VSCodium (Open VSX callbacks even when installing extensions from disk with updates disabled, JSON schema auto-downloads, extensions making their own unsolicited requests, ...),
- Electron (dictionary updates from Google servers, no way of disabling; includes any application running on top of upstream Electron, such as Signal, Discord, etc.),
- GoldenDict (audio samples fetched from the Internet on word look-up, no way to disable)
Of course, this is nothing compared to Windows [0] and macOS [1], but the malpractice of making Internet connections without asking, by default, has unfortunately been finding its way everywhere since modems stopped making audible sounds.
Having read about PRISM and seen the leaked dashboards of Paragon Graphite (said to be used by ICE), and with LLMs bridging the gap between mass and targeted surveillance, I don't want any of this.
Per se? No, maybe with the exception of GNOME Shell which literally runs code from the Internet unsandboxed. Can the traffic they silently generate be used for malicious purposes? Absolutely.
Wasn’t it KDE that had malware in its theme store not too long ago? Let that sink in for a bit. You changed around some icon themes and it executed arbitrary code.
And let’s not pretend that kde wouldn’t have an extension system if it could - but it’ll never have one because implanting one in that c++ spaghetti nightmare will never happen.
But if not, I'm not criticizing GNOME in isolation here. It's just what I use and what I'm most familiar with. KDE has the same issues and it does have an extension system too. It's called KNewStuff.
Problem with updates is that without automatic ones, users could stay on outdated systems and possibly get hacked through some vulnerability(of which there are many). While on the other hand, having explicit confirmations for each network request would be crazy annoying.
Maybe some middleground of having the tool OP sent built-in would be a good option.
I run all my systems with all outgoing connections blocked by default, and yes, it is annoying.
But it wasn't always this way, and so, I don't think it has to be. People just need to start paying attention to this.
The impact of a lot of those vulnerabilities would be mitigated if the affected programs didn't connect to the network in the first place.
As for updates in general, I really like the model adopted by Linux update managers and BSD port systems. The entire repository metadata is downloaded from a mirror and cached locally, so the search terms never leave your machine. Downloads happen from the nearest mirrors, there's no "standard" mirror software (unless rsync and Apache count?) so they don't report what was downloaded by whom back to any central system and you can always host your own. Everything is verified via GPG. And most importantly, nothing happens on its own; you're expected to run `apt/dnf update` yourself. It won't randomly eat your bandwidth on a metered connection or reveal your OS details to a public hotspot.
Simple, non-invasive, transparent, (almost) all-encompassing, and centrally configurable.
It contains Firefox and Chromium. You are right that they may call home, but at least it's very limited and easily configurable. Could be too much for you but fine with me. Also Debian does change their config by default to minimize privacy issues: https://news.ycombinator.com/item?id=32582260
It's far from easy in the case of Firefox [0], and the last time I tried, some .mozilla.com domains would still get pinged. Chromium doesn't even have an official guide. The only options I found to be reliable are source-level patches, i.e. ungoogled-chromium and LibreWolf.
Note that LibreWolf still leaves some of the stuff on for you to manually disable (dom.push.connection.enabled, extension updates).
It's not, though. There simply wasn't enough malware to worry about. Why would I run a firewall when I was unlikely to ever encounter a malicious program?
I mean, supply chain attacks are a thing that could have happened even in the earlier days. Linux almost got backdoored in 2003.
Also with the number of remote code execution exploits that have occurred in Web browsers over the years it's hard to know for sure if what you installed hasn't been hijacked unless you spent all your time on gnu.org
I helped administer the CheckPoint commercial version of this before 2010 in a large enterprise (Checkpoint Integrity it was badged as). Really good product though we did have some bugs with it - I do remember the developers from Israel got involved and were very capable.
It mostly worked exactly as you would want a desktop firewall to, and integrated nicely with Cisco VPN tech, so you could ensure Integrity was operating correctly before fully opening up the tunnel for access to corporate assets.
This reminded me of running Kerio Personal Firewall. When Kerio ended I switched to either ZA or Comodo firewall, one of them introduced a neat feature of running executables in containers. Made clicking random things so much easier. But the best part with all of these was restricting windows to where it could barely do anything. "RandomXYZ.DLL wants to execute random what and connect to random where? I dont think so MS." lol
I remember switching from Win95 to NT4.0 just to be able to use SoftICE properly under Windows without all the stability problems, it was an incredible time! SoftICE felt like absolute wizardry at the time.
Wow. Insane throwback. I think I first learned about ZoneAlarm from some PC magazine my parents bought for me. Completely forgot about this great piece of freemium!
if anyone else suddenly started wondering, PC magazines still exist in physical form. There are even still Linux magazines that come with installer CDs for distros. And all kinds of other magazines as well, like for Mac computers, for photo editors, for Raspberry Pi etc.
Back when people would try to winnuke others on IRC, the Linux guys would know who sent them the packet and call them out in the channel (and then usually ban them)
I ran ntop on a router in 2001. It had a highly insightful overview of traffic with nice looking diagrams and everything. There hasn't been anything like that since as far as I'm aware.
ZoneAlarm otoh, was snakeoil. Programs that ran at the same privilege level (typically everything) could bypass it in various ways.
There was also Tiny Firewall which got bought by Computer Associates around 2005. Probably the most complicated or fine grain control for me at that time in Windows XP.
This is what I used! At some point I managed to block DHCP lease renewals on my computer, and Internet would always stop working after a given timespan. Took a good while to figure out I caused the problem myself.
It is probably easier these days when you have a phone to fall back on for if you break the internet on your computer.
Playing with your router is still a pain though, especially if you don't have a device with an Ethernet port. You learn all sorts of fun things like "If you change your router's IP address you get logged out of its management at the old IP address" and "Oh, that's what subnet mask means, weird."
No, the Windows firewall in its default configuration does not restrict outbound connections in any way. Any application can make any outbound connection it wants. If an application attempts to listen for incoming connections from external sources and there is not an existing policy, Windows will pop up a dialog asking the user if they want to allow this and if so whether it should be allowed to listen on all networks, only networks marked as "private", or for domain-bound corporate computers only networks where the domain controller is reachable.
It can be manually configured with very detailed policies, but you have to know where to go to find those controls.
It's been a while since I used ZoneAlarm or Little Snitch, but the last time I used either one the default behavior was instead that any connection attempt or attempt to listen for which there was not a policy would result in a dialog showing all the details about what application is looking to connect to or receive connections from what as well as a variety of options for creating a policy or even not creating a policy and just deciding whether that one connection would be allowed.
Also back when I used ZoneAlarm I had dialup so the taskbar addon they had which showed realtime bandwidth usage and what applications had active connections was really useful. It also had a big red "Stop" button that would immediately disable all connections, which thinking about it in retrospect really makes me miss the more innocent days of the internet.
Shameless plug: for anyone who wants something fully open source and terminal-based, I maintain RustNet (https://github.com/domcyrus/rustnet). It's a bit different because it's a TUI for real-time connection monitoring with deep packet inspection, not a firewall. No blocking/rules, but it's cross-platform (Linux/macOS/Windows), the entire codebase is open, and it sandboxes itself after init via Landlock with capability dropping.
Okay hear me out, I use little snitch for a while. Great product. Love finding out what phones where. I make every single request (except my browser, because I'm fine with their sandbox) block until I approve.
Recently I was wondering how you really have to trust something like little snitch given its a full kernel extension effectively able to MITM your whole network stack.
So I went digging (and asked some agents to deep research), and I couldn't find much interesting about the company or its leadership at all.
All a long way to say, anyone know anything about this company?
Disclaimer: I'm the developer of Little Snitch for Linux. Regarding MITM concerns: The eBPF component, which actually sees all the traffic, is Open Source (GPLv2). You can review it on Github and verify whether it sends any data to user space: https://github.com/obdev/littlesnitch-linux
But the trust issue is still real, the daemon has to run as root because it needs to watch for new mounts and keep a table of file system roots up-to-date, even after loading all the eBPF programs. As a root process, it can technically do whatever it wants. Unless you limit it with a kind of mandatory access control (SELinux or similar).
This is the very first release and we will probably come up with a more restricted permission requirement in the future. For the moment, I try to catch up with bug reports. There seems to be more diversity in the Linux landscape than I had expected.
I'm happy to see this on Linux and I really appreciate the open-sourcing of the eBPF component.
I maintain rustnet, a passive network monitor in the same eBPF + libpcap space, so I ran into a lot of the same issues. Wanted to share what has been working for me on the privilege side, in case any of it is useful for v2.
rustnet ships with setcap 'cap_net_raw,cap_bpf,cap_perfmon+eip' instead of setuid-root. During startup it loads the eBPF programs, opens the pcap handle, and then drops all three caps before touching any packet data. It clears the ambient set, sets PR_SET_NO_NEW_PRIVS, and applies a Landlock ruleset that restricts the filesystem to /proc plus configured log paths and blocks TCP bind/connect on 6.4+ kernels. Code is in src/network/platform/linux/sandbox/ if you want to have a look.
On the "needs to watch mounts" point, totally fair that Little Snitch needs live mount visibility, but I think it is achievable without staying UID 0:
- Watching for mount changes: poll() on /proc/self/mountinfo with POLLPRI wakes on every mount table change from a completely unprivileged process (this is what systemd and mount(8) use internally). Alternatively, an eBPF program on the mount/umount/move_mount tracepoints can be loaded at init and stream events via a ring buffer, with no continued cap cost after load.
- Resolving an arbitrary PID to its binary across container mount namespaces: CAP_SYS_PTRACE is enough for that. The /proc/PID/root magic symlink does the namespace translation inline inside the kernel pathwalk, so open("/proc/12345/root/usr/bin/firefox", ...) opens the right file in the right container's view without ever calling setns(), which is what would otherwise need CAP_SYS_ADMIN (the new root).
> All a long way to say, anyone know anything about this company?
Yes, they are indie Mac developers who have been in business for more than 20 years, and Little Snitch for Mac is beloved by many users for a long time.
Like how it happened for Bartender, another macOS app which required a lot of permissions. It was sold to a company and they told no one, until a user noticed via the now defunct MacUpdater that the app signature changed.
Ben Surtees (Bartender’s original developer) burned all the good will accumulated over years in one moment. Never again can anyone trust software under that name.
Bartender was not a supply chain attack! The app was sold for monetary reasons to another developer for monetary reasons.
There were no targets involved. There were no nation-states involved. There were no attacks involved. You might not like the new developer, but this whole discussion of a nation-state and 9 figure payoff is totally ridiculous.
Various intelligence agencies are willing to pay 2-3M for a working exploit for iphone or android. I think that they would be fine with paying 50M for a userbase that has a high population of devs, admins, etc. Being able to backdoor someone like this in the right organization down the line is probably worth 50M.
> Various intelligence agencies are willing to pay 2-3M for a working exploit for iphone or android.
Little Snitch is not a working exploit for iPhone or Android.
> I think that they would be fine with paying 50M for a userbase that has a high population of devs, admins, etc. Being able to backdoor someone like this in the right organization down the line is probably worth 50M.
No, sorry, this is absurd. A ton of products have a high population of devs, admins, etc. These are not getting acquired by intelligence agencies. Give me one example. There's nothing inherently valuable about this population.
Who is a Little Snitch customer worth 50M to attack? Name them.
Depends on the target and what you can get. Think about Bartender, an app requiring an insanely high level of trust and permissions, which was quietly sold.
If you know of someone specific you want to target who uses it, the investment could pay off.
For example, we know from your blog posts that you use LittleSnitch. Someone who wanted to target you might do a lot to spy on you by buying LittleSnitch, probably.
Think of your own apps, too. I don’t think you’d do the same that Ben Surtees did and sell everything in secret, but then again I don’t personally know you. You may have a price that I’m not aware of. For that reason alone, even as I trust the current code is not nefarious, I can never give StopTheMadness access to every website and can only use it selectively, which is inconvenient.
The point is that it shows it can happen. You’re a browser extension developer, surely you know how often it happens that developers of popular extensions are approached by shady businesses and sometimes do even sell.
> You can dream up a bunch of absurd hypothetical scenarios, but they are not the reality.
As someone else has pointed out to you, not hypothetical.
> Nobody wants to target me. Nobody cares about me. I am insignificant.
You give yourself too little credit. I know of several developers and other people with influence who use your extensions with complete trust. Compromising you means compromising them, which means compromising even more people. Jia Tan has aptly demonstrated you don’t need to directly attack your final target, only a link in the chain, even if it looks insignificant.
> surely you know how often it happens that developers of popular extensions are approached by shady businesses and sometimes do even sell.
Yes, developers of free extensions who sell for a pittance.
I don't have a popular extension. My extension is relatively expensive and thus unpopular. I don't have enough users to be interesting to shady businesses. My extension is more valuable to me than to anyone else, because I, one person, can make a living from it.
> As someone else has pointed out to you, not hypothetical.
That link seems a bit silly. There's a screenshot with no explanatory context whatsoever. There's a list of items, many of which look quite mundane and uninteresting. Certainly it is not suggesting acquiring the company for millions of dollars. It sounds like someone—could even be an intern for all we know—is interested in attacking the app from the outside.
> I know of several developers and other people with influence who use your extensions with complete trust. Compromising you means compromising them, which means compromising even more people.
What is the value of compromising these people? Oh noes, the CIA can now write Daring Fireball articles!
> Jia Tan has aptly demonstrated you don’t need to directly attack your final target, only a link in the chain, even if it looks insignificant.
What chain? I have no third-party dependencies. If someone can compromise Apple's operating systems, then my software or Little Snitch is the least of our worries.
I do specifically and intentionally avoid using NPM, because of frequent compromises. Little Snitch is not even JavaScript, so no worries there.
> My extension is more valuable to me than to anyone else, because I, one person, can make a living from it.
I believe you, and as a fellow indie developer trust you and your intentions and that you’re careful to not be compromised. But if I’m being honest with myself I don’t have concrete proof of any of those. So I trust but also try to limit the blast radius if anything goes wrong. Does that make sense? I think you might agree there.
Your blog helps with that trust and with understanding the human behind it.
> Certainly it is not suggesting acquiring the company for millions of dollars.
Alright, yeah, I see we’re talking a bit past each other in that regard. You’re right that’s how the conversation started (before I joined in) but I don’t care for that angle fully either. I agree there are more plausible ways to achieve the objective.
> Oh noes, the CIA can now write Daring Fireball articles!
Not sure that’d be a downgrade. Maybe they could fix the Markdown perl script, too. Joking aside, I think there would be better targets, like someone on Apple’s Passwords team.
> What chain? I have no third-party dependencies. If someone can compromise Apple's operating systems
I don’t mean it in the sense of software dependencies, but in the sense that some app you use would compromise you. You know macOS’ permissions are mostly security theatre. We know people inside Apple use third-party apps. I can imagine ways of exploiting that, given a bit more knowledge of people from inside (which could be gathered from working there for a while, trawling social media, maybe reading Gruber’s emails, …).
> I do specifically and intentionally avoid using NPM, because of frequent compromises.
> I don’t mean it in the sense of software dependencies, but in the sense that some app you use would compromise you. You know macOS’ permissions are mostly security theatre. We know people inside Apple use third-party apps. I can imagine ways of exploiting that, given a bit more knowledge of people from inside (which could be gathered from working there for a while, trawling social media, maybe reading Gruber’s emails, …).
You seem to be waffling here between targeted and untargeted attacks.
There's a world of difference between compromising me or an Apple employee and compromising my software or Apple's software. You don't magically get the latter from the former.
Untargeted attacks are just looking for the usual stuff, e.g., money. They don't care about who the victims are or what else they have.
It would require a targeted attack to insert mallicious code into my software or into Apple's software. You claim, "I can imagine ways of exploiting that," but I don't actually believe you. If you can imagine it, then explain exactly how.
There's no evidence that anyone is targeting my software or that anyone has any reason to target my software. Even if I downloaded a typical malware app from the web, that wouldn't result in malicious code getting shipped in my software.
I'm not aware of anyone on the Apple Passwords team using my software, so if someone were trying to attack me to get to them, that's seems a bit fruitless, to use a pun. In any case, the chain from compromising me, to compromising my software releases, to compromising an Apple engineer, to compromising Apple software releases, is convoluted to the extreme and would require much more specifics than anyone has given here (or is capable of giving).
In any case, I'm quite careful—though not tin foil hat paranoid—about which software I download and run on my Mac, and I've never downloaded malware in more than 20 years as a Mac user. Obviously I'm careful about my own privacy and security, since I use Little Snitch too!
> You seem to be waffling here between targeted and untargeted attacks.
Why do you think it matters? Little Snitch is used by enough people that it would be completely worthwhile as just an asset. With an infinite budget you don't look for the exploits once you have the target; you accumulate the exploits, and use them as you get targets.
I don't know how you think these apps are useful for small-time criminals to exploit, but governments somehow wouldn't be able to figure out a use for them. It reeks of "I have nothing to hide."
Maybe they use Little Snitch just to figure out what you're running, use another exploit to get into that, get blackmail material on one of your family members through connections made from files on your computer, and offer not to release it and to donate $500K to your project (that they'll set up for you, and will come from some obscure European foundation's fund), or "invest" (with no expectation or even mechanism for getting a return) into your LLC if you insert code into your software. Or even simply accept a pull request, which will be totally deniable if the code gets caught, and the pull request eventually traced to a Chinese/Russian/Iranian/North Korean IP.
I have no idea what evidence you expect people to leave. The goal is not to leave evidence. Why would someone announce that they were interested in you or targeting you?
Yes, the number is silly. But that makes the danger even more relevant. They could really get it for a couple million to a couple of people, and double or triple that payment (or stretch it out over a long period) to make sure everybody knows to shut up about it.
(Taking this reply as an excuse to write a concurring rant...)
Also, once you've compromised somebody's integrity and got them on the payroll, why not use them for other things? They can join other projects, they can sit on foundation boards, they can become tech media personalities, etc., etc....
There's nothing tinfoil about this. It's cheap and easy. You could subvert every open source project in the world for less than the cost of one fancy plane, or a few fancy missiles. The CIA went in on a crypto company, got it to weaken everyone's crypto, and likely killed the son who inherited it from the previous owner. "Nation-state buying Little Snitch" is not some crazy fantasy, it's a mundane scenario (I'm sounding like LLM today, I think.) Even though OpenSnitch could be compromised even more cheaply, they show all their code.
Also, aggressors don't just use carrots, they use sticks. The Altman sister stuff for example (true or not, works even better if it's true) certainly seems like a stick. Top of the world, then suddenly a jury (easily subverted by a state) puts you in prison or takes away control of your company, and now you're killed (or "kill yourself") in prison or otherwise. Now your widower and your sister own the company, and they say yes to everything. If my multi-billionaire brother molested me, you'd never hear about it because he would have trivially given me enough money to forget about it and him. I wouldn't be filing any lawsuit. Makes me suspect that he's being resistant to something.
> Said motivation could be a nation state handing them $XXX million dollars
You're missing the most important part of the motivation here: why in the world would a nation-state give a damn about Little Snitch, especially to the tune of $XXX million dollars?
A nation-state could pay $XXX million to your significant other to spy on you. But again, a nation-state doesn't give a damn about you.
>why in the world would a nation-state give a damn about Little Snitch, especially to the tune of $XXX million dollars?
Per user hacked, it can be very cheap¹ compared to bribing anyone. And give data/access that SO can't get.
State is not interested in you until it does. Being Jewish, Polish, Gypsy, Gay. Or just WrongThinking. Or maybe it becomes super cheap and easy to process all information?
1: it can even be free. You either give us backdoor to all your users or you rot in jail. Here's a complementary beating up or pictures of your kids, to argument our position further.
> it can even be free. You either give us backdoor to all your users or you rot in jail.
It is already a thing, at least in UK and AU [1]:
> Both countries now claim the right to secretly compel tech companies and individual technologists, including network administrators, sysadmins, and open source developers – to re-engineer software and hardware under their control, so that it can be used to spy on their users. Engineers can be penalized for refusing to comply with fines and prison; in Australia, even counseling a technologist to oppose these orders is a crime.
Well, that is obvious, is it not? It means They are interested in The Plan and have enough power that a vague comment is all you gonna get. Cannot have Them finding out that we are on to Them. Though of course, The Plan already accounts for that, so They already know and will do Something about it. Want facts? Wake up, do your Research!
disclaimer: I co-develop (FOSS) Little Snitch / Open Snitch inspired firewall but for Android
> little snitch given its a full kernel extension
On macOS, don't think Little Snitch needs kernel exclaves / extensions. Apple provides userspace ("Network Extension") APIs (however limited) for apps like Little Snitch to use (instead of pf).
> effectively able to MITM your whole network stack
"MITM" means something else, anywho... if network observability (not firewall) is the primary need, cross-platform (GUI) sniffers like Sniffnet exist: https://github.com/GyulyVGC/sniffnet
The gold standard, which I haven't been able to achieve, is to be able to do a pi-hole/adguard style centralized control where I can allow youtube but block youtube shorts. All solutions I have seen talk about on-device setup which isn't an option given that I don't want to manage it on a per-device basis.
Because of the way youtube serves shorts the exact same way it serves any other video it sounds like a man-in-the-middle proxy server would be needed. which to enforce would still require per device config(loading corp style keys). A per device config that would probably be trickier than a shorts killer browser extension.
This is why DoH makes me nervous. Once the embedded ad engines(cough smart tv's) figure it out, we will no longer be able to mitm our dns services. Or to put it more plainly pi-hole will stop working. An open question, Any good way to block DoH? Or are heuristics the only answer?
An unenforceable option would be to set up an independent youtube frontend. https://invidious.io/
My opinion on shorts is a little more generous, sure they are generally brain-cell destroying bottom of the barrel clickbait nonsense. But that can also be said about most of the rest of youtube. What I hate specifically is the shorts doom-scrolling interface. It turns out a "short" can still be viewed on the normal interface. So I use a browser extension to turn shorts urls into normal urls.
You would have to break E2E encryption, no? I think, at the very least you still would have to manage new TLS certificates per device to MITM yourself. I mean, doable, but also kinda nasty.
I used Little Snitch on Mac a few years ago and liked it, though I wasn't a fan of how (necessarily) deep it had to be in the OS to work. It felt like one of those things where, the moment you have any kind of network connectivity issue, it's the first thing you need to disable to troubleshoot because it's the weirdest thing you're doing.
I guess what I'd really like is a middleware box or something that I could put on my home network, but would then still give the same user experience as the normal app. I don't want to have to log into some web interface and manually add firewall rules after I find something not working. I like the pop-ups that tell you exactly when you're trying to do something that is blocked, and allow you to either add a rule or not.
I'm probably straddling some gray area between consumer-focused and enterprise-focused feature sets, but it would be neat.
I am the same, used Little Snitch for a few years back in the late 2000s, I think like 2010 until a few years back when I moved fulltime to Linux. Back then, my parents had an iMac and I was the designated "IT" person to keep it running efficiently. My siblings had a bad habit of installing games and hack software on it for their games. I ended up purchasing a license and after the first few hours/days of configuring allow/block lists, it worked pretty well. It earned the label of "Little B*ch" from them since it would stop their gaming hacking apps from connecting and wrecking havoc. Eventually I learned to keep them on a standard user account and separate admin for installing software.
Long story you didn't ask for. Like I said, I haven't used Little Snitch in a while. I'll give this a whirl this weekend. What I have done over the past few years is run AdGuard Home on a min home server. This has helped keep ads undercontrol in our hoursehold and I have an easy "turn off adguard for 10 mins" in homeassistant for the wife so she can do some shopping online since it can occasionally break some sites, but overall they tolerate adguard and think it's a good middle ground. I have a few block lists, nothing too crazy or strict to avoid breaking most sites. On the desktops/laptops, they all run FireFox w uBlock origin.
How deep it was in the OS was exactly what I liked about it. I only wished it were open source so I know what exactly is happening with that level of access.
Just tried it on my laptop. Unfortunately, my laptop got extremely hot about 10 seconds after installation. The resource monitor showed that it was eating up all of my laptop's CPU. I panically stopped the service and uninstalled it before I could even open the web UI. It was a really poor first impression.
I just tried littlesnitch and it did not resolve very many ips to domains, which is pretty basic. It also failed to identify most processes, and they were grouped under "Not Identified". It appears these are known limitations of the Linux version [1]. So for that alone I need to stick with opensnitch.
[1] "Little Snitch for Linux is built for privacy, not security, and that distinction matters. The macOS version can make stronger guarantees because it can have more complexity. On Linux, the foundation is eBPF, which is powerful but bounded: it has strict limits on storage size and program complexity. Under heavy traffic, cache tables can overflow, which makes it impossible to reliably tie every network packet to a process or a DNS name. And reconstructing which hostname was originally looked up for a given IP address requires heuristics rather than certainty. The macOS version uses deep packet inspection to do this more reliably. That's not an option here." -- from https://obdev.at/products/littlesnitch-linux/index.html
Regarding unidentified processes: Little Snitch daemon must have been running when the process started in order to identify it reliably. It's best to reboot after installation so that Little Snitch starts before everything else. I should probably note this somewhere.
And regarding failed reverse DNS names: Little Snitch is sniffing DNS lookups. If lookups are encrypted, there is little it can do. We usually recommend DNS encryption at the systemd layer, not at app layer. This way we can see lookups on 127.0.0.53 and the actual lookup sent out is still encrypted.
Also, it's currently only sniffing UDP lookups, not TCP. The eBPF part is already very close to the complexity limits (700k instructions of allowed 1M) and adding TCP parsing would exceed this limit. It should be possible to forbid TCP port 53 with a rule, though. Some complex DNS lookups will fail, but routine things should still work.
The thing is, 127.0.0.53 is a fallback. The real default upstream is nss_resolve, which talks to systemd-resolved via non-DNS protocol on a UNIX-domain socket. Ubuntu disabled this in favor of the less-featured fallback. If you insist on sniffing DNS, you need to add instructions to disable the native nss_resolve module by not including it in /etc/nsswitch.conf.
If I don't know who my machine is talking to, the information is not very useful. So there needs to be a fallback on some level.
Perhaps there should be a mode where littlesnitch just does its own lookup using the system-configured rDNS, for example from the ui or for specific processes, etc? It should be cached if it is a recent lookup, so minimal performance implications; and offloaded to the system rDNS resolver, so minimal instruction set.
Not all "hostname lookups" by applications happen over DNS (or the DNS is done by something like systemd-resolved, which is often using encrypted lookups), so in many cases, depending on NSS configuration (e.g. 'file', 'resolve', 'db', 'nis', 'mymachines', 'libvirt', 'winbind', ...) this would never work?
I guess that makes sense, since it's pretty new. OpenSnitch is great software in terms of functionality but I find the UI lacking. If LittleSnitch can keep the same functionality, while improving the UI, I'm switching. My other current concern here is that the LittleSnitch UI is just a Webview and I think it would be much better if there was a native option (ideally GTK-based for me, but Qt would also be acceptable). Webviews are slow and full of bloat.
"I researched a bit, found OpenSnitch, several command line tools, and various security systems built for servers. None of these gave me what I wanted: see which process is making which connections, and in the best case deny with a single click." https://obdev.at/blog/little-snitch-for-linux/
I've used OpenSnitch for years, and while LittleSnitch definitely has a better UI for showing which process is making which connections over time, OpenSnitch does a pretty good job here. I get a modal popup when a program that hasn't made a connection tries to make a connection, and I can either allow/deny in one click, or further customize the rule e.g. allowing ntpd to connect, but only to pool.ntp.org on port 123.
Where LittleSnitch is definitely ahead is showing process connections over time after said process has been allowed.
Personally I'd be fine with a commercial license with source available here... the issue isn't the price, it's the fact that you're asked to MITM every network connection you make under the control of a binary blob.
I think it's fair to ask that a developer choosing to build a thing that requires that kind of access should be expected to err on the side of transparency.
There is a ton of software that lives on because it matters to the developer(s). I know "but mah monetization" is huge on this forum but it's not an all encompassing rule and it does not completely reflect the existing reality.
Strong disagree on this stance. You want to use the software? Cool, pay for it. Need access to source? It's on github, go nuts. Want to change it? Sure, feel free, but whoever uses it should pay the original developer. You can even charge extra for your modifications. Don't like the terms? Too bad - feel free to rewrite from scratch.
FOSS simply isn't sustainable if you want to make a living out of it. It protects a lot of user freedoms - even those that don't actually matter to users that much - at the expense of the rights of developers. There are a lot of ways that developers could be paid and users would still be protected (have access to source and the right to modify). The only ones benefitting from the current situation are BigTech.
Who are we to dictate terms to or divine the intentions of someone who releases software with say the MIT license? It might sound surprising but a lot of developers just want to share their work altruistically. There are some you couldn't pay if you wanted to. It's all voluntary.
> FOSS simply isn't sustainable if you want to make a living out of it.
This is probably true enough. Yet there are a million open source projects that existed, some for decades. There has go to be another way and another motivation.
> even those that don't actually matter to users that much - at the expense of the rights of developers
I would assume those developers would use a different license or even create their own terms.
> The only ones benefitting from the current situation are BigTech.
Paying the original developers will not change this. Big tech is big. They take whatever they can, sometimes killing the original project in the process. Perhaps a license like GPL is the solution to that particular problem.
I don't mean to come off snarky. I do agree with a lot of the things that you're saying but I see the free software movement as a completely voluntary and human thing. You could not get rid of it if you wanted. Paying for it is an auxiliary thing and concentrates too much on the wrong thing IMO. A lot of free software developers are already gainfully employed, some are millionaires. Yes some are struggling but then they are still voluntarily sharing their work with the whole world. That must mean they have their valid reasons for doing so.
The developer isn’t accepting a job offer to develop it, they’re accepting donations. That’s literally how the software devs for Opensnitch choose to receive payment.
Wow. I have used Little Snitch on Mac for years, love this!
If anyone from obdev is reading, please give us a way to pay for it, even if it stays free :), I'd love to support development and would happily pay something between the price of Little Snitch and Little Snitch Mini.
I used to use a Windows firewall which basically hijacked a bunch of WinAPI calls and let me approve/deny every request. Trying to be a good secure boy I ran this setup for a while but it was exhausting. Every single action needed dozens of approval windows. After a while I removed the software. I reckon it is good situationally though, trying out a new program for first time (that isn't risky enough for a VM or sandbox), might be good to turn on a tool like this.
There was a similar Show HN from 3 weeks ago.
https://news.ycombinator.com/item?id=47387443 (open source too) - and there is a live window from all the machines in the swarm. https://dialtoneapp.com/explore - but only 2 so far. Maybe LittleSnitch can generate more data than this? Could end up an immune system for bad actors.
Anything new to get much better performance from low-spec machines that is idiot-proof is a game-changer.
Congrats to Linux users on getting a great tool from a quality development shop. Objective Development is one of our (Mac users) exemplars for attention to detail and fit & finish.
Congrats to Objective Development for expanding their well-loved tool to a new platform. You guys rock.
Little Snitch is bound to the API provided by Apple. The NEFilterDataProvider API calls `handleNewFlow()` only after sending out the first IP packet.
Version 6 added DNS encryption and in principle we could filter lookups (similar to PiHole) at this level. That brings other issues, though: This filter is system-wide, so process-specific rules (and overrides) would not work. And results can be cached by mDNSResponder. So when a blocklist causes an issue, you may not be able to fix it by simply disabling the blocklist. But it's still something we consider.
I've been telling people about ya'll's DNS leaks for over a decade [3] — glad to finally hear back — most people won't believe me [0] until this flaw is demonstrated on their specific machine (easy enough). Those already using LittleSnitch will then typically set up better filtering (e.g. DNS white/blacklist, PiHole, et.alius).
And until the behavior is fixed, I will keep spreading the good word. Does the Linux version have this same flaw (i.e. backend requirements similar to Mac initial IP leak)?
----
A very neat product (LittleSnitch), but I stopped using it solely for above reason [1]. IMHO, this flaw should be better documented in your installer/docs.
[0] e.g. they'll lament "there is no way the developer would allow that sort of leak/behavior!" Their denial is a helluvadrug
[1] I had a 5-user site license, IIRC. Shortly after purchasing, I discovered above leakage so stopped using entirely [v3 user 33TEWP20B0-724KY-5XE522FEAC [2]]
[2] Go ahead and blacklist/cancel the above registration (it's a manyyearsold version, barely used) – my current mailing address is in my user profile (no longer use email/phone). Would love to help/feedback to make your product better. Would also love a refund (all these years later, on principle)
Please see my response to OD [I presume /u/littlesnitch is OD representative]. Nobody is disputing their "greatness" — I'm just criticizing a flaw in their approach to domain name filtering.
Hopefully OD will refund my original license (unused for many many many years, after I discovered this flaw). That would be good, in principle; good business. Hopefully OD will be more forthcoming in this vulnerability (or better disclose it) — or better yet: fix the unbelievable behavior.
Do you understand that you can't redirect the question addressed to you to the devs if that question questions your own statement by pointing out that some important details are not attended to?
Probably should throw it out there that I'm building something inspired by littleSnitch for windows. Currently a bit stealthy about it. But when I crowd source the funding for a code signing cert I'll get it out there. Lots of inspiration from LittleSnitch, in spirit if not actual code.
I'd be curious to hear additional details if you can share - got a timeline, or somewhere I can enter my email address for updates? I'd love to alpha/beta test if you're looking for testers.
I've been a GlassWire user for years, which partially fills the role of LS, but not very well. Aside from the many performance issues I've seen, it's missing a lot of LS essentials. To be fair, I think the focus of GlassWire is more about visualizing traffic on your Windows computer, but I definitely believe there is a need for better Windows network software for power users.
Awesome. I always felt Linux was missing a per-application firewall. I didn't dig much into it but at least iptables didn't have rules for that when I looked.
Incredible. LittleSnitch is must-have for macOS and trying to get equivalent functionality on Linux was painful. So very happy to see this, and very happy to give the developers at Objective Development my money.
In linux, I trust most distro apps to run with network access without any sort of firewall. And for apps from internet, just put them in bubblewrap or run with flatpak without access to homedir, network, audio, video etc. depending on program.
It just depends on the UI frameworks available to developers and their interest in building something good-looking. Different UI frameworks are available for different platforms, and there are only a few good ones that are cross-platform. Qt and GTK are pretty common for linux apps and typically don't look great.
Is that true? If so, that’s not a good sign. I remember how impressed I was by ZoneAlarm in the early 2000s asking permission for itself to connect to the Internet, using the exact same dialogue it presented for any other program, with no dark patterns suggesting that the user should give preferential treatment to it.
Doesn't seem to be, I can see LittleSnitch itself connecting to yoyo.org and obdev.at. GP may be referencing a past bug, either in LittleSnitch or macOS.
I'm so surprised that so few people have heard of Portmaster, it's been around for years and runs on Linux (and Windows if you must). And if you don't need traffic history it's free.
I’ve been researching the “best” way to build a little outbound network proxy to replace credential placeholders with the real secrets. Since this is designed to secure agents workloads, I figured I might as well add some domain blocking, and other outbound network controls, so I’ve been looking for Little-snitch-like apps to build on.
I’ve been surprised to find that there aren’t a ton of open source “filter and potentially block all outbound connections according to rules”. This seems like the sort of thing that would be in a lot of Linux admins’ toolkit, but I guess not! I appreciate these guys building and releasing this.
Something almost no firewalls get right is pausing connections (NOT rejecting them) until I've decided whether to allow or not. The only firewalls I've seen do this are Little Snitch for Mac, and Portmaster for Windows (before they made it adware / started locking existing local features behind the subscription).
Firewalls don't do this because they are built at the wrong layer to do proper pending calls. It's too narrow of a design space for most firewalls to care.
True, most firewalls aren't built to pause for user input. But then again, that's why almost no firewall software is suitable for this user experience.
I use Portmaster (on Linux) and I have never seen ads (either in the app or apps that get their DNS from Portmaster) on it. About the only thing I saw different between the free version and the base level paid for version was traffic history and weekly reports (and badges on Discord if that's your kind of thing).
Both used to be free. And you may not consider it advertising when unavailable features exist in the free UI just to tell you they're paid, but I do. Especially when they used to be free.
OpenSnitch seems to do this just fine? Unless I’m misunderstanding your point. Connections seem to just block until I take an action on the dialog. Now, if an application itself has specified a short timeout (looking at you, NodeJS-based stuff), that obviously doesn’t help. But for most software it works great.
eBPF is very limited in the code complexity you can achieve. DPI on QUIC, for example, needs a lot of cryptography. That's simply not possible in eBPF. DPI on ordinary TLS still requires that you collect enough network packets to get the name, hold them back until you have a decision and then re-inject them. Holding back packets is not even possible at the layer where we intercept. And even if we find a layer to do this, it adds enough complexity that we no longer pass the verifier.
You are referring to the TCP three way handshake problem here. The macOS version is bound by the API provided by Apple: We get the API call for filtering only after the three way handshake has started.
The Linux version is limited in complexity. It has to decide immediately. This has the consequence that no packet leaves the machine if the connection is denied, but on the other hand it means that it's easier to trick. The macOS version can inspect the first packet sent (deep packet inspection) to find the remote host name in TLS headers. The Linux version relies on heuristics: The most recent lookup seen which returned the IP address determines the name. This part is Open Source and you can inspect the algorithm.
Haven’t tried LittleSnitch, but from what I see it’s on par as far as features go. LuLu’s UI could use some improvements, but otherwise it’s perfectly fine for the job.
I'm glad people are building stuff for Linux, but the people who actually want something like this have likely already been using Opensnitch for years. I'm certainly not going to spend $60 for something that has been doing the job for free.
I know it sounds crazy at this point, but with popular YouTubers switching to Linux, gamers overall well-aware of Steam on Linux advantages and switching as well, plus popular software like LittleSnitch getting ported, 2026 can without irony be named as Year of Linux Desktop, right?
I did the switch in 2013 and haven't missed it. For games I ran vga_passthrough and later VFIO and others until pretty recently (I think right after covid I switched to steam directly on linux)
Reminds me about schools of thought on rates of change:
> ## Accelerating Change [One School]
>
> Our intuitions about change are linear; we expect roughly
> as much change as has occurred in the past over our own
> lifetimes. But technological change feeds on itself, and
> therefore accelerates. Change today is faster than it was
> 500 years ago, which in turn is faster than it was 5000
> years ago. Our recent past is not a reliable guide to how
> much change we should expect in the future.
>
> Strong claim: Technological change follows smooth curves,
> typically exponential. Therefore we can predict with fair
> precision when new technologies will arrive, and when they
> will cross key thresholds, like the creation of [AI].
>
> Advocates: Ray Kurzweil, Alvin Toffler(?), John Smart
https://www.yudkowsky.net/singularity/schools
For Linux desktop users. A bit of tongue-in-cheek but that's pretty much the argument that I've heard in some circles ("it works for us and not going away anytime soon - why waste time convincing others?").
I think there is a lot of talk (and this is good), but very little action. Market share is still incredibly low for LNX. I believe only a small subset of people actually attempt the jump from WIN to LNX (since most just want to play their games and run their programs without hassle) and then quickly realize that its tougher than they anticipated and swiftly return to WIN.
This is true, but also the original comment still stands: Linux desktop usage outside developers was so low that it was barely worth mentioning before, so even a small uptick like this is a serious change, and it's how bigger changes start.
I definitely don't think it's even the likely outcome, but for Linux to get serious traction this is how it has to start: power users but not the traditional developer crowd start actually moving, and in doing so produce the guides, experience, word of mouth, and motivation that normal people need to do so, alongside the institutional support from Valve to actually fix the bugs and issues.
It remains to be seen if a critical mass will find it usable long-term, but if it were to happen, this is how it would look at the start, and Microsoft are certainly doing their best to push people away right now, although I suspect the real winner is more likely to be Apple with the Macbook Neo sucking up more of the lower end.
> Microsoft are certainly doing their best to push people away right now
According to a speculative blog post by Eric S. Raymond in September 2020, Microsoft is literally moving towards replacing Windows' internals with Linux. Unfortunately, that post is now unreachable, but searching for "eric raymond article about windows being replaced with a linux kernel" finds many third-party references to it and summaries of it.
5% on the steam survey though. The jump isn't quite as big from previous years as it seems as they did some corrections to the statistics this year, but 5% is nothing to sneeze at.
I wouldn't be too exited. Statistics like this are very problematic.
For example, I have Steam installed on my Macbook pro and I occasionally play a single very simple game there. Does that make me a macOS gamer? of course not. The vast majority of games I want to play don't work on macOS.
I suspect that most of those 5% are just Linux users who have steam installed and play a small amount of games. Some probably just installed it to check what's available and don't play anything.
Everyone I know who is a "serious" gamer, as in exited about upcoming releases of AAA games is using Windows.
Indeed. The bigger problem is also that consistently the most played games are multiplayer competitive titles with anti-cheat software that is only written for Windows (and sometimes MacOS). I suppose this issue will solve itself, once enough people start playing on Linux. Then developers will be forced to support that too in order to not lose too much of their player base, but we are still a far cry from this threshold.
As someone who did make the jump, it was actually a lot easier than I anticipated. I encourage others to do the same. The only games I can't play are some AAA multiplayer games I wasn't particularly interested in anyways.
You are overthinking it. It is neither a strategy nor keystroke saving (although technically with shift its 4 keystrokes as opposed to 5 for Linux and quite a few saved for Windows). I just typed that without thinking probably because it looks better and reads a bit easier (subjectively).
Android/Google does not fulfill the spirit of that. Yes it’s technically Linux, but it’s not what one expects from a Linux experience. We all know this, we all know Linux is under the hood, but “Linux phone” is basically shorthand for more user control, more open source aspects, more secure/private, and far away from companies like Google/apple/etc. Android phones do not fill that request even with graphene and such. Google still has too much control.
Also unrelated, but more linux gamers proves my personal observation that on the spectrum of computer literacy gamers are just below powerusers and programmers. We see more less technical people migrate over to Linux gradually and now it's gamers turn. Well, that's kind of obvious for everybody except Microsoft apparently.
Wifi has been working out of the box for close to 20 years now. On some computers with old Broadcom cards, you have to enable non-free drivers. What model are you using?
WiFi works fine if there are drivers for whatever WiFi chip you have.
Unfortunately there are no standards for OS to talk to WiFi devices like exist for many other types of hardware, so it’s not possible to make generic drivers.
Wifi and Bluetooth are pretty decent now. As far as I can tell the biggest blockers are:
* Laptop battery life. Still in the "it's fine; I get 5 hours!" stage.
* Wayland & graphics. It's still a mess. Getting there though. Probably will be ok in about 5 years I'd guess.
* RAM management. I don't know why nobody cares about this but when Mac or Windows run low of RAM I don't even notice. With Linux it either hard freezes and reboots, or hard freezes for like 5 minutes and then kills a completely random program. How is that ok? My solution here was to upgrade both my computers to 128 GB of RAM, but that isn't really a viable option today!
* Generally bugginess. Both KDE and Gnome are just not as rock solid as Windows 11. I know I'll get downvoted for this but I haven't experienced a single crash on Windows 11 (and no ads or bloatware because I did research and used the LTSC edition). In KDE, much as I love it, the taskbar crashes regularly and I cannot make head nor tail of the completely random order it wants to put windows in. You can't even drag them into a sensible order. Gnome was not much better.
Still KDE is a lot better now than it was in the kidney bean days so I reckon in another 5 years it will probably be pretty solid too.
The core issue is simple and uncomfortable: through automatic updates, a vendor can run any code, with any privileges, on your machine, at any time.
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If the author is serious about this, then they should make their own program completely open source, and make builds bit-for-bit reproducible.
For all I know, the proprietary Little Snitch daemon, or even the binaries they're distributing for the open source components, contain backdoors that can be remotely activated to run any code, with any privileges, on your machine, at any time.
This is correct, of course. But I currently can't make the entire project Open Source. My other option would be to keep it completely private (wrote it mostly for myself in the first place).
I think it's still better to make it public and only partially Open Source so that some people can benefit from it. If you don't trust us, that's completely reasonable, just don't install it.
Related - I'm working on launching Watch.ly[0] (human-in-the-loop for remotely approving network and file system access for agents) in the next week or so. It works similarly, via eBPF (although we can also fall back to NFQUEUE). Supporting 5.x+ linux kernels[1], osx, and windows.
Did not know about LittleSnitch, will definitely check it out.
Will there ever be anything like Comodo Firewall's HIPS firewall on Linux [0]? I remember when firewalls like ZoneAlarm could detect keyboard hooks from keyloggers and such. Comodo Firewall has had this for over a decade, but unfortunately they are not free anymore. For how open Linux is, it surprises me you can't handle things apps are doing on an alert by alert basis, and not just network permissions. Firewalls used to detect DLL injections, apps creating script files to run, adding stuff to start up. Now it seems firewalls only means network detection.
An operating system is roughly broken into three parts: the kernel, the core system tools, and the shell (the desktop environment and/or the CLI shell). Linux: Linux kernel, GNU coreutils (usually), KDE/Gnome/etc + CLI shells. macOS: XNU, BSD userland + launchd/etc, Aqua/Cocoa. Windows: NT kernel, Win32/WinRT/etc, Windows Shell.
The systems LittleSnitch uses to do packet inspection are very much OS-specific. There's no generic standard for doing high-performance packet inspection. XNU and Linux are *very* different kernels. Linus Torvalds built Linux from scratch as a monolithic kernel because he wanted a Unix-like OS that wasn't encumbered. XNU is based on the Mach microkernel though XNU is a hybrid or monolithic kernel, not a microkernel. The point is, they have very different heritage and very different systems for... well pretty much everything. So "just *nix under the hood" is kind of true but also completely besides the point as far as packet inspection goes. And even then, while there are a lot of similarities between the core system tools of Linux and macOS, they're still quite different and unless you're limiting yourself to POSIX-standard interfaces (which are only a fraction of the system), you're not going to be able to use the same code on both systems.
More the opposite. macOS is a veneer of nix, but underneath it is the XNU microkernel. Lots more nuance since Apple took over and added a lot of their own performance and API improvements to
You're correct, but for a bit more context: The macOS kernel is XNU, which is derived from/based on the Mach kernel, but heavily modified. The kernel itself is open source but some drivers/kernel extensions are not so it's not actually usable (unless you provide your own implementations of those).
On macOS, it requires access to /dev/bpf. That's why we added filter rules for bpf there.
On Linux, we intercept at a level where packets already have an Ethernet header. I hope that Paqet injects before* this layer, but only a test can give the proof.
I know everyone today is used to upgrading every 5 seconds, but some of us are stuck on old software. For example, my Linux machine keeps rebooting and sucks up power in suspend mode because of buggy drivers in 6.12+, so I'm stuck on 6.8. (which is extra annoying because I bought this laptop for its Linux hardware support...)
In theory, it could be possible to get the requirement down to 5.17, but I don't get around the verifier constraints on pre 6.12 kernels. Maybe somebody who is more experienced with eBPF and the verifier can help. This part is Open Source and you can replace it.
Does anyone know how the blocking functionality works? I worked on some eBPF code a few years ago (when BTF/CO-RE was new), and while it was powerful, you couldn't just write to memory, or make function calls in the kernel.
Is there a userland component that's using something like iptables? (Can iptables block traffic originating from/destined to a specific process nowadays?)
eBPF is extended in every kernel version. There is a layer where you get network packets and return a verdict. Little Snitch uses this type of eBPF function. You can look at the sources on Github.
Back when I was still using macOS I loved Little Snitch and was a paying customer. And I agree nothing on Linux comes close. Would it be technically feasible to also provide this as a Flatpak to support immutable distros like Bazzite?
I’m not aware of flatpaks specifically having th capability to run system software, daemons, etc. Some other immutable packaging formats should be able to (systemd-sysext at least, and snap iirc).
Giving it a shot right now. Very easy setup, intuitive UI, but a lot of requests' processes are not identified (while they could easily be identified, as they belong to the browser that has some, but less, identified calls)
Little Snitch must be running when the process starts in order to identify it correctly. You get less "Not Identified" if you run it for a while, or you should get none if you reboot and Little Snitch can start before everything else.
I would love to fix this requirement, but have not found a way yet.
They are still restricting iCloud Private Relay to Safari for the most part. iOS is really wanting for privacy improvements to close the gap between marketing and reality.
Fun fact: iOS lets developers spy on when you _dismiss_ notifications:
Ever instantly angry-swipe-to-clear a DM notification soon as it hits your lockscreen from someone who upset you? Zuck knew y'all had beef.
Clear notifications before bed and in the morning? All those companies could know a bit more about your routine than you would've otherwise revealed if weren't in the habit of using those apps at those times.
--
The kinds of tiny things that would be pretty inconsequential on their own but that you figure maybe the Apple tax would help you avoid.
Just because I did not port the parser for it to Rust. And I thought that the lsrules format is rare for blocklists. If there is popular demand, we can add it.
So if this is free to use on linux, what is to stop someone from doing what Colima did to Docker? Aka make a tiny Linux VM on MacOS and package Little Snitch within that?
It barely has any of the features of the MacOS version, there is no shortage of cracks for Little Snitch, and there is Lulu. Other than that, I am not sure.
Little Snitch requires packet inspection. If you ran it in a Linux VM, it will inspect packets within the VM. So... kind of useless for monitoring connections on the host.
> For keeping tabs on what your software is up to and blocking legitimate software from phoning home, Little Snitch for Linux works well. For hardening a system against a determined adversary, it's not the right tool.
What would be the right tool to harden in a similar way to little snitch on mac? Meaning intercepting any connection and whitelisting them reliably.
cool to see eBPF used for a desktop firewall instead of just ddos packet dropping. the note about bpf map overflows is super relatable, dealing with that on bare-metal is a pain.
my question is... if the tracking maps fill up completely, does the daemon fail-open or fail-closed?
There is currently no treatment of errors because I would not know how to handle them anyway. There are two tables which can overflow affecting the filter: the table of open flows and the table of recent DNS lookups. The table of flows just fills up, meaning that we cannot store state about new flows. Without state, we can't attribute a process to them and end up evaluating rules on each packet. I guess that blocklists would still work, but more specific rules would not be applied (and the default decision would be taken, whatever you have configured).
The DNS lookups, on the other hand, are LRU. If the table overflows too soon, we won't be able to derive names for IP addresses and name-based rules would fail.
> You can find Little Snitch for Linux here. It is free, and it will stay that way.
Don't worry, the authors know that there's no point in charging Linux users. Unlike Mac users.
So you might as well make it $0 and the (Linux) crowd goes wild that they don't need to pay a cent.
However...
> I researched a bit, found OpenSnitch, several command line tools, and various security systems built for servers. None of these gave me what I wanted: see which process is making which connections, and in the best case deny with a single click.
OpenSnitch is open source. You don't need to trust it as you can see the code yourself. Little Snitch on the other hand, is completely closed source.
Do you still trust them not to do self-reporting or phoning home, even though it is $0 and closed source?
We have not detected a targeted attack yet.
On the Mac side, we are safe: No dependencies on any third party libraries. Only Apple.
On the Linux side, there is no single big vendor such as Apple who provides all the necessary libraries. I have tried to choose reputable sources from crates.io only, but to be honest, I don't know a secure solution to the problem.
> They don't build their own machines or write their compilers or write their own crpyto code or ... so many other things.
An attack on any of these things has nothing specifically to do with the developers of Little Snitch and would have vastly more widespread and important effects.
Why would you even be talking about Little Snitch if a compiler were compromised?!? Your paranoia here is bizarrely narrow. Little Snitch would be the least of our problems in that case.
The comment was asking about preventing a compromised supplier for the developers.
A supply chain attack can be anywhere in the supply chain to the target. If I, the end user, am the target, then a supply chain attack compromising the developer of LittleSnitch is effective.
I may then be a conduit to compromising other software or components, and would both I and LittleSnitch would be part of the supply chain that could be attacked targeting them.
Many supply chain attacks aim to run malware on the end-users machine to harvest authentication tokens, etc. So pretty much everyone here who is a developer is the target.
> So pretty much everyone here who is a developer is the target.
Are you going to have this same discussion about every piece of software every mentioned on Hacker News? Why are we having it for Little Snitch specifically?
> I'm not even going to respond to this ridiculousness.
Why is it ridiculous? If you have electronic access to something of value and broadcast that fact on the internet, you’re at risk of a physical attack. That’s not controversial? Companies make employees do training about this for a reason.
> If you have electronic access to something of value and broadcast that fact on the internet, you’re at risk of a physical attack. That’s not controversial? Companies make employees do training about this for a reason.
You're talking as if all all "value" and all "risk" is equal, when they're definitely not. You can't equate a megacorporation with a little indie developer. Nobody cares about the latter.
I am a software developer, and I broadcast that fact on the internet. But nobody is coming to Wisconsin to hit me on the head with a wrench. That's just a silly paranoid fantasy.
If anyone hits me on the head with a wrench, it would be not be a nation-state but rather a two-bit local mugger who has no idea who I am and just wants cash from my wallet. I live in a pretty safe area though.
Yeah just yolo install whatever, it’s not like applications or libraries such as axios which have a decade of trusted history would all of a sudden become malicious and do nasty things to developer machines, just chill, everything’s fine.
WTF? This is not an acceptable comment on HN, no matter who or what you're replying to. This style of commenting is not what this site is for, and destroys what it is for.
>> I still don't know why anyone thinks that, among all developers in the world, a little indie Mac developer is getting targeted specifically.
> The same people who targeted the open source uncommercial library axios last week?
axios is an NPM package. Little Snitch doesn't use NPM. Thus, these people must be pretty damn incompetent if they were trying to target Little Snitch.
> Access to little snitch would be worth millions to the right party.
This is a bold claim with no evidence. I don't think it's true.
Of course, getting data uploads past little snitch is an exercise in triviality. For instance, using DNS tunneling. Sending requests to unrelated servers, ideally on AWS or some other cloud, so you have no idea at all who's behind the server and the firewall can't realistically block it, where the info can be retrieved by another party.
Which one? Mac or Linux? For the Linux Snitch, just stop the service. For the macOS Snitch, you need to move the app to the trash via Finder. Only Apple can remove the network extension and they do this only when deleted via Finder.
i will never understand why people will flock to this but opensnitch which is just better, fully open and has existed for longer (on linux) gets ignored.
"Little Snitch for Linux is built for privacy, not security, and that distinction matters. The macOS version can make stronger guarantees because it can have more complexity. On Linux, the foundation is eBPF, which is powerful but bounded: it has strict limits on storage size and program complexity. Under heavy traffic, cache tables can overflow, which makes it impossible to reliably tie every network packet to a process or a DNS name. And reconstructing which hostname was originally looked up for a given IP address requires heuristics rather than certainty. The macOS version uses deep packet inspection to do this more reliably. That's not an option here."
Is this a limitation of the eBPF implementation? Pardon my ignorance, I'm genuinely curious about this.
Yess, the return of the actually good landing page for the technically-minded. Now all they need to do is roll back the macOS one that looks and reads like it was designed by a marketing agency that knows nothing about computers (or even Little Snitch itself).
It’s not really necessary on Linux. Linux systems work without 40 invisible background services phoning home to the mothership to leak your hardware identifiers for FAA702 collection.
I run both (LS on Mac, at least), they do different things - pi.hole is a great ad blocker which applies to all of the devices on your network. Little Snitch is doing something different - it tells you every call that every app you use is making, and allows you to approve or deny each one. So, you can block telemetry for apps, or you can block certain apps from contacting certain servers, or you can just use it to watch what apps on your system are calling out to where.
To clarify, I'm aware that pihole is not intended to run on a client OS, and doesn't monitor at a process level. I'm focused on the intended effect rather than the process itself (blocking malicious/ad servers). And I think I framed my initial question incorrectly as if LS and PiHole as subtitutes. It's perfectly fine and even preferrable to use both as layered protection. I'm just thinking however when it comes for bang-for-buck it seems like PiHole is the better value proposition if you could only set up one.
pi.hole is primarily billed as an ad blocker, but the fundamental way it works is by applying a curated set of DNS lists that are blocked (commonly telemetry and ad servers), and the admin dashboard which is just a web page (therefore works on all platforms, smartphones included) will do the same thing: it tells you every call that every app on every device on your network is making, and you can approve or deny it. You can curate your own list as well and block servers/connections you don't want on the network.
LS afaik operates in the same area where it's intended to be used for privacy. I guess I could see it being useful for people who don't have admin access to their router, but for people who do have such access I would think the benefits of network-wide DNS monitoring/blocking would outweight the costs of having to configure your router settings.
Yeah, if you're just looking for ad blocking, you're right, pi.hole is the better bet.
Little Snitch is intended for per-process, per-connection blocking - for example, you may need, eg, an Instagram uploader app to contact Meta's servers, but an unrelated app should not be able to (and even in the case of the hypothetical IG uploader, you can get very fine grained about the controls - media.facebook.net, not telemetry.facebook.net). In that way, LS does have some advantages over pi.hole in that space - You'd need to set up every single item that you normally get for free from a blocklist, but it gives you much finer control over what's getting blocked and much better visibility into what connections your processes are trying to make.
Again, I don't think Little Snitch is the right answer if you're looking for ad blocking specifically, and if that's the extent of your privacy concerns, pi.hole's a better bet. Little Snitch is a per-application connection monitor and firewall - it _can_ block ads, but that's not its primary purpose.
LS seems to not be claiming any security promise on Linux because it can't make any guarantees given eBPF limitations. But the entire purpose is different and there is very little overlap in my view. PiHole is entirely (I think?) just applying the blocklist made easy. LS allows you to build the blocklist in real time.
I would guess that to the extent the blocklists include things that are loaded by applications and not websites, they are almost entirely built by users of something like LittleSnitch or OpenSnitch. This is also entirely doable with wireshark logs, but I think that requires more infrastructure to build into usable lists.
LittleSnitch isn't for ad blocking (only), it is for tracking/blocking/allowing ALL connections from various processes. PiHole only blocks DNS requests to known ad servers.
Completely different thing. A littlesnitch type thing is for all traffic. Pihole is a DNS query thing that prevents various ad content from being loaded. It's also trivially easy for a malicious application with network access to bypass any instance of pihole on your LAN by doing its own DNS over HTTPS lookups to its own set of server(s) by IP.
You might be surprised, there are plenty of low effort attacks out there that just install a crypto miner and phone home periodically without doing much to cover it up.
> The macOS version can make stronger guarantees because it can have more complexity. On Linux, the foundation is eBPF, which is powerful but bounded: it has strict limits on storage size and program complexity. Under heavy traffic, cache tables can overflow, which makes it impossible to reliably tie every network packet to a process or a DNS name.
> And reconstructing which hostname was originally looked up for a given IP address requires heuristics rather than certainty. The macOS version uses deep packet inspection to do this more reliably.
> That's not an option here.
>
> Source: https://web.archive.org/web/20260409002901/https://obdev.at/products/littlesnitch-linux/index.html
The above feels like an utter AI slop nonsense, sorry. I believe eBPF, the Linux Kernel feature, is absolutely capable for accuracy and perfect processing of network traffic.
Have you ever checked Calico or Cilium, or at least, Oryx?
eBPF programs are able to accuratly process network traffic in high performance, but the amount of CPU instructions you can use is limited. Otherwise it would not be high performance. This limits the complexity of in-kernel processing.
Thank you for the response. Yet, how the heck the CPU instructions you inject in (that are being processed within the same network processing) limit the capabilities of the flow, if you literally put your calls within the same networking context? Please provide any actual document that proves your point.
I have, but in the scopes of Kprobes non-network but memory. Here, I am sure you haven't at this point. I also provided projects you may check prior stating another nonsense. Instead, you could also provide some more evidence you disagree with.
I'm not a Little Snitch or Open Snitch user, I wonder if these firewalls are able to block requests done with the use of some other, allow-listed program.
Say I run a script `suspicious.py' and I deny this script from making any network requests. I also have firefox which is allowed to make any HTTPS requests. If suspicious.py does something like:
will this request be blocked?It depends. Little Snitch for Linux has a two level namespace for processes. It takes the process doing the connection and its parent process into account when evaluating rules.
Also: If an interpreter is run via `#!/bin/interpreter` in the script binary, it makes the rule for the script file path, not the interpreter. This does not work when running the script as `interpreter script`, though.
This gets even more involved when you consider things like loading libraries, there's also the impact of calls like OpenProcess/WriteProcessMemory/CreateRemoteThread (Windows-land versions, though I'm sure similar exists elsewhere).
The "good" Windows firewalls like Outpost and Zone Alarm used to have features to catch this, they'd detect when a process tried to invoke or open a running process which had internet access. They'd also do things like detect when a process tried to write a startup item. This went by names like "Leak Control" but it was basically providing near-complete HIDS features with local control.
With the literal rules described it would not be blocked. A more detailed rule (in Open Snitch at least, not as familiar with the other variants) could match e.g. whether the process's parent tree contained the python binary rather than just if python is the process binding the socket.
OK, I see, so a limitation is also that I cannot block an individual script, I need to block a Python interpreter.
Not necessarily (with Open Snitch at least), it just depends how complex you want to make your firewall rules and what the specific goal is (block this specific script, block scripts which try to do this activity, block connection to evil.net, block python scripts, etc).
The more granular one gets the more likely they aren't really meaning to ask how to do it in the firewall layer though. E.g. if we take it further to wanting to prevent python -c "specific logic" it's clearer what you can do in the firewall is not necessarily the same as what's practical or useful.
Would it silently allow or would you still get the notif or whatever (iirc from littlesnitch years ago)?
The allow rule for Firefox is what would suppress the prompt. You probably don't want to have a prompt for every Firefox connection though, so you'd need to come up with some kind of ruleset (or get very annoyed :D).
The SELinux MAC policy should restrict which files and ports each process may access. In general, most modern distro have this feature, but normal users do not go through the rules training and default enable flag setup. =3
Tried it on Fedora 43 (6.19.11 x86_64) and it loaded all CPU cores, dumped 50K lines in the journal and failed to start.
> Error: the BPF_PROG_LOAD syscall returned Argument list too long (os error 7).
> littlesnitch.service: Consumed 3min 38.832s CPU time, 13.7G memory peak.
Sorry, we have not tested on Fedora before release. Did not expect so much interest in the first hours after release...
I have now installed Fedora in a VM (ARM64 architecture, though) and it does load, but cannot identify processes. I'm investigating this now.
The other issue seems to be with eBPF compatibility. That's a moving target and I'll investigate next. But resources are limited, I'll need some time to dig into this.
There's some good feedback in the GitHub issue on the subject, seems to happen on slightly newer versions of the kernel than the one you've tested on and affects other distros like Arch as well. I'll keep an eye on the discussion and test again once updates are ready.
Someone already created an issue for it: https://github.com/obdev/littlesnitch-linux/issues/1
From the download page on the website:
"Note: Little Snitch version 1.0.0 does not currently work with the Btrfs file system! Btrfs is used by default on Fedora, so Little Snitch does not currently identify processes on Fedora. We are working on an 1.0.1 release to fix the issue as soon as possible!"
I was looking for a comment like yours. Same issue, in my case only eating up half of my cores but with 100% utilization, webUI not working.
Your average Linux experience.
And the second most upvoted comment is someone seriously asking if 2026 if the year of Linux desktop...
Yeah, because no third party program has ever crashed on any other OS.
Come on, this is an absurd comment. Linux has its issues, this is not a serious example of what is keeping normal people from using Linux as a desktop OS. Normal people are not installing the first release of a privacy networking tool that requires you to OK connections.
99,9% of the time, you download an exe or a DMG, you can be pretty sure it's going to work. Even 3 star github repo.
Only on Linux you get weird bug, compilation issues, etc.
After all, you have windows, macos and then you have Linux : debian, Ubuntu, fedora, arch, opensuse. That's almost like 5 different os just for Linux.
Sure you can use flatpack and force people to download 2gb installation for something that requires 20mb on windows and macos. That excludes all of the people who don't have fiber internet.
At this point I'm convinced that those developing Linux don't want it to be an os for casuals and prefer to stay in their small, niche community. That's fine by me but it makes claim of Linux desktop year laughable, which I was referring to.
The take on flatpaks is such an uninformed one. DMGs on MacOS come with all the dependencies bundled in, which make them essentially just as big as the comparable flatpak (minus the shared runtime that gets installed once)
Seriously, the amount flatpak misinformation that people hold onto is absolutely wild. Ex: I have had to show people it does differential updates because they don't bother to read the output.
Flatpaks are easily the best gui desktop app experience for users we have today.
That's not the user experience though, the user experience is it says "go to the discover app and install <program>" and they do that and it just works. Downloading a tarball is not the normal way to install stuff on Linux, and given everyone has phones where the standard is "install on the app store", it's hardly some new experience, in fact, it's more natural for normal users.
This is brand new open source software with like 3 stars on github
Recently I was wondering how viable it is to launch a niche, paid tool for Linux. I found that this is a very rare model, most tools are either just free, supported by sponsorship, supported by some paid cloud-based service that accompanies the tool, use an open-core model with paid add-ons.
I wonder if the decision of Little Snitch to make the Linux version free forever was also informed by this "no way to make money selling tools on Linux" wisdom or if there was another motivation. It seems that if any tool has chances of making decent money on Linux, a product like Little Snitch, which is already well established, with working payment infrastructure would be a good candidate.
Many from linux crowd are slightly paranoid and ideological.
I'm as a linux user very reluctant to install anything proprietary that has such sensitive info as my network traffic and would rather use opensnitch or any other foss fork.
The same time I don't mind to pay for open-source, I donate several thousands USD per year to FOSS projects. But I guess I'm in a minority here and if you make the whole stack open-source you're not going to make many sells really.
> Many from linux crowd are slightly paranoid
Slightly? There are quite a few tin foil hat comments on this submission.
Well, it's all relative and depends on perception.
I tried to briefly explain a typical i-own-my-computer mindset regarding the linux monetization question from the parent comment.
I can pay for cool stuff I can trust, but the "I can trust" part is very tricky.
You call it paranoia, I call it zero tolerance for enshitification.
It's like the Nazi bar problem. You need to be vigilant to prevent the thing you rely on becoming yet another platform for Microsoft to exfil your personal data to NSA servers.
As the author of Little Snitch for Linux, I can tell you what drives us: we are a small company where people (not investors) make the decisions. It was a personal choice of mine, driven by a gut feeling. I'm curious about the outcome...
As a paying customer, I wasn't expecting this so thank you! Can you expand more on your gut feeling? Also, I have different security expectations on Linux vs MacOS. Would you ever consider open sourcing the daemon?
The author talks about his motivation right here: https://www.obdev.at/blog/little-snitch-for-linux/
It's not that arcane.
Nice to have this as an extra option, but being a linux user I value openness of code. I am pretty content with opensnitch + opensnitch-ui.
i have been pretty happy with opensnitch. ui improvements are always welcome although what might be really interesting would be some sort of plug-in system that allows for an agent to watch my interactions activity and the outbound connections and only flag things that seem surprising. also maybe some kind of improvement over the pop-up (maybe get rid of them entirely and add some kind of cli wrapper that allow-lists child processes).
This has the author's blog post on it https://obdev.at/blog/little-snitch-for-linux/
I remember before Little Snitch there was ZoneAlarm for Windows[0] (here is a good screenshot[1]). No clue if the current version of ZoneAlarm does anything like that (have not used it in 2 decades). I always found it weird that Linux never really had anything like it.
[0]: https://en.wikipedia.org/wiki/ZoneAlarm
[1]: https://d2nwkt1g6n1fev.cloudfront.net/helpmax/wp-content/upl...
I wrote a program similar to this for AmigaOS many, many years ago. I would have been inspired by ZoneAlarm or a program like it.
I've just found it and uploaded it to github. Looking at the code, I can see my horrible C style of the time. There's probably bugs galore.
https://github.com/JetSetIlly/Direwall
If I remember correctly, it runs as a commodity and patches the socket library. Interestingly, the socket library was not re-entrant (unusual for Amiga libraries) so I had to patch the Exec OpenLibrary() function to monitor the loading of new copies of the socket library. But it's been a long time so memories are hazy.
It'll be interesting to see if it is still compiles and runs for modern AmigaOS, if any active Amiga programmers are around to see.
What I really liked about ZoneAlarm wasn't just that it was a very nice technology - and it was; but also that it got the user expectations and training right from a very early stage.
It was quite insistent on the fact that it would be "noisy" at first as it queried all the programs you ran, but would then quieten down once it had been "trained". It got that across in clear, simple language.
I think it was so successful because it got the soft side of its security job right as well as the hard part. It's certainly why I recommended it to anyone at the time...
Was working as an IT consultant. We got a call from an international manufacturer in the area for support. Local lead IT manager took down the firewall which infected their computer network around the world. All they wanted were bodies to help clean systems and apply OS updates.
My personal computer had ZoneAlarm on it. It became ground zero for reporting about infected systems. They ignored systems they thought were save; CISCO phone system running on Windows server and other backend devices. The company then bought a few licenses to run their own laptops.
It is such a same that Microsoft destroyed _ERD Commander_ and other quality tools which assisted in the clean up.
> [ZoneAlarm] I always found it weird that Linux never really had anything like it.
There was simply no need for it. GNU provided most of the software, spyware was unknown.
Only since comercial vendors package for linux and bring their spyware along, the desire to inspect network rose.
This is such a naive view on computer security. It’s not just about spyware, which is also not exclusive to commercial vendors.
What else is this about? Debian repositories still contain no malware and if you install software exclusively from them, you'll be safe.
Run OpenSnitch for a while and you'll quickly realize how much of your system does phone home. Off the top of my head:
- GNOME Shell (extension updates without a way to disable this, weather),
- GNOME Calculator (currency exchange rates),
- NetworkManager (periodic hotspot portal checks in most configurations),
- GDB (debuginfod enabled by default),
- Firefox (extension updates, push notifications, feature flags, telemetry, ..., some parts cannot be disabled),
- VSCodium (Open VSX callbacks even when installing extensions from disk with updates disabled, JSON schema auto-downloads, extensions making their own unsolicited requests, ...),
- Electron (dictionary updates from Google servers, no way of disabling; includes any application running on top of upstream Electron, such as Signal, Discord, etc.),
- GoldenDict (audio samples fetched from the Internet on word look-up, no way to disable)
Of course, this is nothing compared to Windows [0] and macOS [1], but the malpractice of making Internet connections without asking, by default, has unfortunately been finding its way everywhere since modems stopped making audible sounds.
Having read about PRISM and seen the leaked dashboards of Paragon Graphite (said to be used by ICE), and with LLMs bridging the gap between mass and targeted surveillance, I don't want any of this.
[0] https://github.com/microsoft/calculator/blob/ffd0519676019a0...
[1] https://sneak.berlin/20201112/your-computer-isnt-yours/
> GNOME Calculator (currency exchange rates),
Which would crash (technically hang) if you blocked it. [0]
[0] https://forums.debian.net/viewtopic.php?p=818264
People still care about these things on Debian. But as is said 20 years ago there was no need, because the default was to be sane.
Are these malware ?
Per se? No, maybe with the exception of GNOME Shell which literally runs code from the Internet unsandboxed. Can the traffic they silently generate be used for malicious purposes? Absolutely.
Wasn’t it KDE that had malware in its theme store not too long ago? Let that sink in for a bit. You changed around some icon themes and it executed arbitrary code.
And let’s not pretend that kde wouldn’t have an extension system if it could - but it’ll never have one because implanting one in that c++ spaghetti nightmare will never happen.
I think you meant to reply to this: https://news.ycombinator.com/item?id=47702680
But if not, I'm not criticizing GNOME in isolation here. It's just what I use and what I'm most familiar with. KDE has the same issues and it does have an extension system too. It's called KNewStuff.
you could always run kwin_wayland and prevent all that phoning home...
Problem with updates is that without automatic ones, users could stay on outdated systems and possibly get hacked through some vulnerability(of which there are many). While on the other hand, having explicit confirmations for each network request would be crazy annoying.
Maybe some middleground of having the tool OP sent built-in would be a good option.
I run all my systems with all outgoing connections blocked by default, and yes, it is annoying.
But it wasn't always this way, and so, I don't think it has to be. People just need to start paying attention to this.
The impact of a lot of those vulnerabilities would be mitigated if the affected programs didn't connect to the network in the first place.
As for updates in general, I really like the model adopted by Linux update managers and BSD port systems. The entire repository metadata is downloaded from a mirror and cached locally, so the search terms never leave your machine. Downloads happen from the nearest mirrors, there's no "standard" mirror software (unless rsync and Apache count?) so they don't report what was downloaded by whom back to any central system and you can always host your own. Everything is verified via GPG. And most importantly, nothing happens on its own; you're expected to run `apt/dnf update` yourself. It won't randomly eat your bandwidth on a metered connection or reveal your OS details to a public hotspot.
Simple, non-invasive, transparent, (almost) all-encompassing, and centrally configurable.
Does it contain Firefox? How about Chrome?
Quote from LittleSnitch:
> Little Snitch for Linux is built for privacy, not security
What's your definion of malware in this context?
It contains Firefox and Chromium. You are right that they may call home, but at least it's very limited and easily configurable. Could be too much for you but fine with me. Also Debian does change their config by default to minimize privacy issues: https://news.ycombinator.com/item?id=32582260
It's far from easy in the case of Firefox [0], and the last time I tried, some .mozilla.com domains would still get pinged. Chromium doesn't even have an official guide. The only options I found to be reliable are source-level patches, i.e. ungoogled-chromium and LibreWolf.
Note that LibreWolf still leaves some of the stuff on for you to manually disable (dom.push.connection.enabled, extension updates).
[0] https://support.mozilla.org/en-US/kb/how-stop-firefox-making...
In firefox, goto about:config and search for url.
You're welcome.
Ads, trackers, general boost to privacy. Not every protection tool is just about malware.
Yeah I will also be safe if I never turn on the PC, but some of us use computers to do actual work.
It's not, though. There simply wasn't enough malware to worry about. Why would I run a firewall when I was unlikely to ever encounter a malicious program?
I mean, supply chain attacks are a thing that could have happened even in the earlier days. Linux almost got backdoored in 2003.
Also with the number of remote code execution exploits that have occurred in Web browsers over the years it's hard to know for sure if what you installed hasn't been hijacked unless you spent all your time on gnu.org
Yes, but the probability of the average user getting pwned was so small that it wasn't worth the constant firewall babysitting.
Completely forgot about ZoneAlarm. I remember using it in the early 2000s!
I read ZoneAlarm and it was like suddenly a part of my brain that went unvisited for 25 years lit up...
WinAmp skins. Alternate shells for Windows(!). Cygwin because I still played too many games to go full Linux.
Yeah...
btw all versions of WinAmp + skins still work great in 2026 even on Win11 :)
It still whips the llama's ass.
I helped administer the CheckPoint commercial version of this before 2010 in a large enterprise (Checkpoint Integrity it was badged as). Really good product though we did have some bugs with it - I do remember the developers from Israel got involved and were very capable.
It mostly worked exactly as you would want a desktop firewall to, and integrated nicely with Cisco VPN tech, so you could ensure Integrity was operating correctly before fully opening up the tunnel for access to corporate assets.
Same. And in a similar vein--AnalogX NetStat Live.
Same... Totally forgot about ZA.
Such nostalgia! I probably forgot about it after switching over to Linux 25 years ago.
Same!
This reminded me of running Kerio Personal Firewall. When Kerio ended I switched to either ZA or Comodo firewall, one of them introduced a neat feature of running executables in containers. Made clicking random things so much easier. But the best part with all of these was restricting windows to where it could barely do anything. "RandomXYZ.DLL wants to execute random what and connect to random where? I dont think so MS." lol
Who remembers BlackICE Defender tho?
https://archive.org/details/BlackICE_Defender
I was there for SoftICE and BlackICE.
Simpler times.
I remember switching from Win95 to NT4.0 just to be able to use SoftICE properly under Windows without all the stability problems, it was an incredible time! SoftICE felt like absolute wizardry at the time.
Wow. Insane throwback. I think I first learned about ZoneAlarm from some PC magazine my parents bought for me. Completely forgot about this great piece of freemium!
if anyone else suddenly started wondering, PC magazines still exist in physical form. There are even still Linux magazines that come with installer CDs for distros. And all kinds of other magazines as well, like for Mac computers, for photo editors, for Raspberry Pi etc.
I learned about it from Leo and Patrick on The Screen Savers
Linux users just browsed firewall logs.
Back when people would try to winnuke others on IRC, the Linux guys would know who sent them the packet and call them out in the channel (and then usually ban them)
Back in the Halo 2 days ZoneAlarm and Cain and Abel were the go-to host bridging and bluescreen programs.
A simpler time lol.
Used to use Outpost Firewall Pro, too.
Good old Halo 2 stand-bying. An absolute plague.
I ran ntop on a router in 2001. It had a highly insightful overview of traffic with nice looking diagrams and everything. There hasn't been anything like that since as far as I'm aware.
ZoneAlarm otoh, was snakeoil. Programs that ran at the same privilege level (typically everything) could bypass it in various ways.
> I always found it weird that Linux never really had anything like it.
OpenSnitch must be like ten years old by now. I think also portmaster is somewhat similar too.
ZoneAlarm, assuming it still exists, would be at least 20 years old.
Back then there was also a nice ~$15 program called Net Limiter which allowed one to cap network speeds individually per program.
It's interesting hw lng it took for linux to get a user friendly application firewall like OpenSnitch
It's because there's no way to make universal kernel modules/drivers, like it is on Windows.
The way to make kernel modules is to submit them to the kernel. Not really sure what a “universal kernel module” really is.
Also that seems irrelevant because it seems this was implemented in eBPF so no kernel modules are required.
For me it was Sygate personal firewall back on windows xp
There was also Tiny Firewall which got bought by Computer Associates around 2005. Probably the most complicated or fine grain control for me at that time in Windows XP.
This is what I used! At some point I managed to block DHCP lease renewals on my computer, and Internet would always stop working after a given timespan. Took a good while to figure out I caused the problem myself.
and that's how you learn...
Shooting yourself in the foot really helps to built intuition!
It is probably easier these days when you have a phone to fall back on for if you break the internet on your computer.
Playing with your router is still a pain though, especially if you don't have a device with an Ethernet port. You learn all sorts of fun things like "If you change your router's IP address you get logged out of its management at the old IP address" and "Oh, that's what subnet mask means, weird."
Sometimes called "high instructional value".
i loved zonealarm! and also pained myself with all the little rules and upkeep lol
It was problematic, so we moved to blackice defender iirc
isn’t this essentially built into Windows these days? although it seems to come with a lot of programs pre-approved.
No, the Windows firewall in its default configuration does not restrict outbound connections in any way. Any application can make any outbound connection it wants. If an application attempts to listen for incoming connections from external sources and there is not an existing policy, Windows will pop up a dialog asking the user if they want to allow this and if so whether it should be allowed to listen on all networks, only networks marked as "private", or for domain-bound corporate computers only networks where the domain controller is reachable.
It can be manually configured with very detailed policies, but you have to know where to go to find those controls.
It's been a while since I used ZoneAlarm or Little Snitch, but the last time I used either one the default behavior was instead that any connection attempt or attempt to listen for which there was not a policy would result in a dialog showing all the details about what application is looking to connect to or receive connections from what as well as a variety of options for creating a policy or even not creating a policy and just deciding whether that one connection would be allowed.
Also back when I used ZoneAlarm I had dialup so the taskbar addon they had which showed realtime bandwidth usage and what applications had active connections was really useful. It also had a big red "Stop" button that would immediately disable all connections, which thinking about it in retrospect really makes me miss the more innocent days of the internet.
Iirc the firewall was already in XP. Maybe earlier but sp2 for sure.
Default allows everything though but you could even set outbound blocking rules. Cumbersome UI and no really good visibility though.
You gonna commit seppuku if you try to add rules with the built in one.
Most of the windows firewalls tools are just front ends for the integrated one with more sensible defaults.
Congrats on the Linux port, this looks very nice.
Shameless plug: for anyone who wants something fully open source and terminal-based, I maintain RustNet (https://github.com/domcyrus/rustnet). It's a bit different because it's a TUI for real-time connection monitoring with deep packet inspection, not a firewall. No blocking/rules, but it's cross-platform (Linux/macOS/Windows), the entire codebase is open, and it sandboxes itself after init via Landlock with capability dropping.
Very nice, I will give it a try later
Okay hear me out, I use little snitch for a while. Great product. Love finding out what phones where. I make every single request (except my browser, because I'm fine with their sandbox) block until I approve.
Recently I was wondering how you really have to trust something like little snitch given its a full kernel extension effectively able to MITM your whole network stack.
So I went digging (and asked some agents to deep research), and I couldn't find much interesting about the company or its leadership at all.
All a long way to say, anyone know anything about this company?
Disclaimer: I'm the developer of Little Snitch for Linux. Regarding MITM concerns: The eBPF component, which actually sees all the traffic, is Open Source (GPLv2). You can review it on Github and verify whether it sends any data to user space: https://github.com/obdev/littlesnitch-linux
But the trust issue is still real, the daemon has to run as root because it needs to watch for new mounts and keep a table of file system roots up-to-date, even after loading all the eBPF programs. As a root process, it can technically do whatever it wants. Unless you limit it with a kind of mandatory access control (SELinux or similar).
This is the very first release and we will probably come up with a more restricted permission requirement in the future. For the moment, I try to catch up with bug reports. There seems to be more diversity in the Linux landscape than I had expected.
I'm happy to see this on Linux and I really appreciate the open-sourcing of the eBPF component.
I maintain rustnet, a passive network monitor in the same eBPF + libpcap space, so I ran into a lot of the same issues. Wanted to share what has been working for me on the privilege side, in case any of it is useful for v2.
rustnet ships with setcap 'cap_net_raw,cap_bpf,cap_perfmon+eip' instead of setuid-root. During startup it loads the eBPF programs, opens the pcap handle, and then drops all three caps before touching any packet data. It clears the ambient set, sets PR_SET_NO_NEW_PRIVS, and applies a Landlock ruleset that restricts the filesystem to /proc plus configured log paths and blocks TCP bind/connect on 6.4+ kernels. Code is in src/network/platform/linux/sandbox/ if you want to have a look.
On the "needs to watch mounts" point, totally fair that Little Snitch needs live mount visibility, but I think it is achievable without staying UID 0:
- Watching for mount changes: poll() on /proc/self/mountinfo with POLLPRI wakes on every mount table change from a completely unprivileged process (this is what systemd and mount(8) use internally). Alternatively, an eBPF program on the mount/umount/move_mount tracepoints can be loaded at init and stream events via a ring buffer, with no continued cap cost after load. - Resolving an arbitrary PID to its binary across container mount namespaces: CAP_SYS_PTRACE is enough for that. The /proc/PID/root magic symlink does the namespace translation inline inside the kernel pathwalk, so open("/proc/12345/root/usr/bin/firefox", ...) opens the right file in the right container's view without ever calling setns(), which is what would otherwise need CAP_SYS_ADMIN (the new root).
> All a long way to say, anyone know anything about this company?
Yes, they are indie Mac developers who have been in business for more than 20 years, and Little Snitch for Mac is beloved by many users for a long time.
Everything has a price though… (I also use little snitch)
> Everything has a price though…
What is that supposed to mean in this context?
Given sufficient motivation the little snitch dev could essentially supply chain attack every user, or even specific users.
Said motivation could be a nation state handing them $XXX million dollars
Or even sell the whole org for say $50M and no one ever mentions anything.
I think the type of users it attracts (techies, crypto ppl, etc) makes it worth more too.
Like how it happened for Bartender, another macOS app which required a lot of permissions. It was sold to a company and they told no one, until a user noticed via the now defunct MacUpdater that the app signature changed.
Ben Surtees (Bartender’s original developer) burned all the good will accumulated over years in one moment. Never again can anyone trust software under that name.
Bartender was not a supply chain attack! The app was sold for monetary reasons to another developer for monetary reasons.
There were no targets involved. There were no nation-states involved. There were no attacks involved. You might not like the new developer, but this whole discussion of a nation-state and 9 figure payoff is totally ridiculous.
> You might not like the new developer
What I didn’t like was the secrecy, that was a breach of user trust. Why wasn’t it announced is the problem.
That's a legitimate criticism. Nonetheless, this subthread started with a comment about supply chain attacks and nation states, which is ridiculous.
> I think the type of users it attracts (techies, crypto ppl, etc) makes it worth more too.
No, this by itself doesn't make Little Snitch or any business worth $50M. You're dreaming. That's a crazy valuation.
Various intelligence agencies are willing to pay 2-3M for a working exploit for iphone or android. I think that they would be fine with paying 50M for a userbase that has a high population of devs, admins, etc. Being able to backdoor someone like this in the right organization down the line is probably worth 50M.
> Various intelligence agencies are willing to pay 2-3M for a working exploit for iphone or android.
Little Snitch is not a working exploit for iPhone or Android.
> I think that they would be fine with paying 50M for a userbase that has a high population of devs, admins, etc. Being able to backdoor someone like this in the right organization down the line is probably worth 50M.
No, sorry, this is absurd. A ton of products have a high population of devs, admins, etc. These are not getting acquired by intelligence agencies. Give me one example. There's nothing inherently valuable about this population.
Who is a Little Snitch customer worth 50M to attack? Name them.
Depends on the target and what you can get. Think about Bartender, an app requiring an insanely high level of trust and permissions, which was quietly sold.
If you know of someone specific you want to target who uses it, the investment could pay off.
For example, we know from your blog posts that you use LittleSnitch. Someone who wanted to target you might do a lot to spy on you by buying LittleSnitch, probably.
Think of your own apps, too. I don’t think you’d do the same that Ben Surtees did and sell everything in secret, but then again I don’t personally know you. You may have a price that I’m not aware of. For that reason alone, even as I trust the current code is not nefarious, I can never give StopTheMadness access to every website and can only use it selectively, which is inconvenient.
> Depends on the target and what you can get. Think about Bartender,
As I said in another comment, Bartender had no target! It was not an attack. An app was sold by one developer to another developer. End of story.
> If you know of someone specific you want to target who uses it
But you don't. And you don't in the case of Little Snitch either.
You can dream up a bunch of absurd hypothetical scenarios, but they are not the reality.
> Someone who wanted to target you
Nobody wants to target me. Nobody cares about me. I am insignificant.
> Bartender had no target! It was not an attack.
The point is that it shows it can happen. You’re a browser extension developer, surely you know how often it happens that developers of popular extensions are approached by shady businesses and sometimes do even sell.
> You can dream up a bunch of absurd hypothetical scenarios, but they are not the reality.
As someone else has pointed out to you, not hypothetical.
https://news.ycombinator.com/item?id=47699068
> Nobody wants to target me. Nobody cares about me. I am insignificant.
You give yourself too little credit. I know of several developers and other people with influence who use your extensions with complete trust. Compromising you means compromising them, which means compromising even more people. Jia Tan has aptly demonstrated you don’t need to directly attack your final target, only a link in the chain, even if it looks insignificant.
> surely you know how often it happens that developers of popular extensions are approached by shady businesses and sometimes do even sell.
Yes, developers of free extensions who sell for a pittance.
I don't have a popular extension. My extension is relatively expensive and thus unpopular. I don't have enough users to be interesting to shady businesses. My extension is more valuable to me than to anyone else, because I, one person, can make a living from it.
> As someone else has pointed out to you, not hypothetical.
That link seems a bit silly. There's a screenshot with no explanatory context whatsoever. There's a list of items, many of which look quite mundane and uninteresting. Certainly it is not suggesting acquiring the company for millions of dollars. It sounds like someone—could even be an intern for all we know—is interested in attacking the app from the outside.
I agree with tptacek: "This is clownish" https://news.ycombinator.com/item?id=13813828
> You give yourself too little credit.
No, I give myself too much credit. ;-)
> I know of several developers and other people with influence who use your extensions with complete trust. Compromising you means compromising them, which means compromising even more people.
What is the value of compromising these people? Oh noes, the CIA can now write Daring Fireball articles!
> Jia Tan has aptly demonstrated you don’t need to directly attack your final target, only a link in the chain, even if it looks insignificant.
What chain? I have no third-party dependencies. If someone can compromise Apple's operating systems, then my software or Little Snitch is the least of our worries.
I do specifically and intentionally avoid using NPM, because of frequent compromises. Little Snitch is not even JavaScript, so no worries there.
> My extension is more valuable to me than to anyone else, because I, one person, can make a living from it.
I believe you, and as a fellow indie developer trust you and your intentions and that you’re careful to not be compromised. But if I’m being honest with myself I don’t have concrete proof of any of those. So I trust but also try to limit the blast radius if anything goes wrong. Does that make sense? I think you might agree there.
Your blog helps with that trust and with understanding the human behind it.
> Certainly it is not suggesting acquiring the company for millions of dollars.
Alright, yeah, I see we’re talking a bit past each other in that regard. You’re right that’s how the conversation started (before I joined in) but I don’t care for that angle fully either. I agree there are more plausible ways to achieve the objective.
> Oh noes, the CIA can now write Daring Fireball articles!
Not sure that’d be a downgrade. Maybe they could fix the Markdown perl script, too. Joking aside, I think there would be better targets, like someone on Apple’s Passwords team.
> What chain? I have no third-party dependencies. If someone can compromise Apple's operating systems
I don’t mean it in the sense of software dependencies, but in the sense that some app you use would compromise you. You know macOS’ permissions are mostly security theatre. We know people inside Apple use third-party apps. I can imagine ways of exploiting that, given a bit more knowledge of people from inside (which could be gathered from working there for a while, trawling social media, maybe reading Gruber’s emails, …).
> I do specifically and intentionally avoid using NPM, because of frequent compromises.
Same, no argument from me there.
> I don’t mean it in the sense of software dependencies, but in the sense that some app you use would compromise you. You know macOS’ permissions are mostly security theatre. We know people inside Apple use third-party apps. I can imagine ways of exploiting that, given a bit more knowledge of people from inside (which could be gathered from working there for a while, trawling social media, maybe reading Gruber’s emails, …).
You seem to be waffling here between targeted and untargeted attacks.
There's a world of difference between compromising me or an Apple employee and compromising my software or Apple's software. You don't magically get the latter from the former.
Untargeted attacks are just looking for the usual stuff, e.g., money. They don't care about who the victims are or what else they have.
It would require a targeted attack to insert mallicious code into my software or into Apple's software. You claim, "I can imagine ways of exploiting that," but I don't actually believe you. If you can imagine it, then explain exactly how.
There's no evidence that anyone is targeting my software or that anyone has any reason to target my software. Even if I downloaded a typical malware app from the web, that wouldn't result in malicious code getting shipped in my software.
I'm not aware of anyone on the Apple Passwords team using my software, so if someone were trying to attack me to get to them, that's seems a bit fruitless, to use a pun. In any case, the chain from compromising me, to compromising my software releases, to compromising an Apple engineer, to compromising Apple software releases, is convoluted to the extreme and would require much more specifics than anyone has given here (or is capable of giving).
In any case, I'm quite careful—though not tin foil hat paranoid—about which software I download and run on my Mac, and I've never downloaded malware in more than 20 years as a Mac user. Obviously I'm careful about my own privacy and security, since I use Little Snitch too!
> You seem to be waffling here between targeted and untargeted attacks.
Why do you think it matters? Little Snitch is used by enough people that it would be completely worthwhile as just an asset. With an infinite budget you don't look for the exploits once you have the target; you accumulate the exploits, and use them as you get targets.
I don't know how you think these apps are useful for small-time criminals to exploit, but governments somehow wouldn't be able to figure out a use for them. It reeks of "I have nothing to hide."
Maybe they use Little Snitch just to figure out what you're running, use another exploit to get into that, get blackmail material on one of your family members through connections made from files on your computer, and offer not to release it and to donate $500K to your project (that they'll set up for you, and will come from some obscure European foundation's fund), or "invest" (with no expectation or even mechanism for getting a return) into your LLC if you insert code into your software. Or even simply accept a pull request, which will be totally deniable if the code gets caught, and the pull request eventually traced to a Chinese/Russian/Iranian/North Korean IP.
I have no idea what evidence you expect people to leave. The goal is not to leave evidence. Why would someone announce that they were interested in you or targeting you?
Yes, the number is silly. But that makes the danger even more relevant. They could really get it for a couple million to a couple of people, and double or triple that payment (or stretch it out over a long period) to make sure everybody knows to shut up about it.
(Taking this reply as an excuse to write a concurring rant...)
Also, once you've compromised somebody's integrity and got them on the payroll, why not use them for other things? They can join other projects, they can sit on foundation boards, they can become tech media personalities, etc., etc....
There's nothing tinfoil about this. It's cheap and easy. You could subvert every open source project in the world for less than the cost of one fancy plane, or a few fancy missiles. The CIA went in on a crypto company, got it to weaken everyone's crypto, and likely killed the son who inherited it from the previous owner. "Nation-state buying Little Snitch" is not some crazy fantasy, it's a mundane scenario (I'm sounding like LLM today, I think.) Even though OpenSnitch could be compromised even more cheaply, they show all their code.
Also, aggressors don't just use carrots, they use sticks. The Altman sister stuff for example (true or not, works even better if it's true) certainly seems like a stick. Top of the world, then suddenly a jury (easily subverted by a state) puts you in prison or takes away control of your company, and now you're killed (or "kill yourself") in prison or otherwise. Now your widower and your sister own the company, and they say yes to everything. If my multi-billionaire brother molested me, you'd never hear about it because he would have trivially given me enough money to forget about it and him. I wouldn't be filing any lawsuit. Makes me suspect that he's being resistant to something.
That’s what i meant. Thanks for reading my mind. :)
> Said motivation could be a nation state handing them $XXX million dollars
You're missing the most important part of the motivation here: why in the world would a nation-state give a damn about Little Snitch, especially to the tune of $XXX million dollars?
A nation-state could pay $XXX million to your significant other to spy on you. But again, a nation-state doesn't give a damn about you.
>why in the world would a nation-state give a damn about Little Snitch, especially to the tune of $XXX million dollars?
Per user hacked, it can be very cheap¹ compared to bribing anyone. And give data/access that SO can't get.
State is not interested in you until it does. Being Jewish, Polish, Gypsy, Gay. Or just WrongThinking. Or maybe it becomes super cheap and easy to process all information?
1: it can even be free. You either give us backdoor to all your users or you rot in jail. Here's a complementary beating up or pictures of your kids, to argument our position further.
> it can even be free. You either give us backdoor to all your users or you rot in jail.
It is already a thing, at least in UK and AU [1]:
> Both countries now claim the right to secretly compel tech companies and individual technologists, including network administrators, sysadmins, and open source developers – to re-engineer software and hardware under their control, so that it can be used to spy on their users. Engineers can be penalized for refusing to comply with fines and prison; in Australia, even counseling a technologist to oppose these orders is a crime.
[1] https://www.eff.org/deeplinks/2018/12/new-fight-online-priva...
1) Little Snitch is not based in the UK or Australia.
2) They are interested in software will billions of users. They are not interested in software with thousands of users.
> Per user hacked, it can be very cheap¹ compared to bribing anyone.
How many users do you think Little Snitch has?
its been known for some time that little snitch and other personal firewalls are established targets of three-letter agencies https://news.ycombinator.com/item?id=13813160
That comment is a screenshot presented with no context, listing a bunch of rather mundane stuff.
"This is clownish" https://news.ycombinator.com/item?id=13813828
Well, that is obvious, is it not? It means They are interested in The Plan and have enough power that a vague comment is all you gonna get. Cannot have Them finding out that we are on to Them. Though of course, The Plan already accounts for that, so They already know and will do Something about it. Want facts? Wake up, do your Research!
disclaimer: I co-develop (FOSS) Little Snitch / Open Snitch inspired firewall but for Android
> little snitch given its a full kernel extension
On macOS, don't think Little Snitch needs kernel exclaves / extensions. Apple provides userspace ("Network Extension") APIs (however limited) for apps like Little Snitch to use (instead of pf).
> effectively able to MITM your whole network stack
"MITM" means something else, anywho... if network observability (not firewall) is the primary need, cross-platform (GUI) sniffers like Sniffnet exist: https://github.com/GyulyVGC/sniffnet
The gold standard, which I haven't been able to achieve, is to be able to do a pi-hole/adguard style centralized control where I can allow youtube but block youtube shorts. All solutions I have seen talk about on-device setup which isn't an option given that I don't want to manage it on a per-device basis.
Because of the way youtube serves shorts the exact same way it serves any other video it sounds like a man-in-the-middle proxy server would be needed. which to enforce would still require per device config(loading corp style keys). A per device config that would probably be trickier than a shorts killer browser extension.
This is why DoH makes me nervous. Once the embedded ad engines(cough smart tv's) figure it out, we will no longer be able to mitm our dns services. Or to put it more plainly pi-hole will stop working. An open question, Any good way to block DoH? Or are heuristics the only answer?
An unenforceable option would be to set up an independent youtube frontend. https://invidious.io/
My opinion on shorts is a little more generous, sure they are generally brain-cell destroying bottom of the barrel clickbait nonsense. But that can also be said about most of the rest of youtube. What I hate specifically is the shorts doom-scrolling interface. It turns out a "short" can still be viewed on the normal interface. So I use a browser extension to turn shorts urls into normal urls.
You would have to break E2E encryption, no? I think, at the very least you still would have to manage new TLS certificates per device to MITM yourself. I mean, doable, but also kinda nasty.
How does it compare to Portmaster?
https://news.ycombinator.com/item?id=29761978
Portmaster – Open-source network monitor and firewall [315 points | 113 comments]
https://news.ycombinator.com/item?id=23539687
Show HN: Block trackers system-wide on Linux/Windows, a Pi-hole “to go” alt
[6 points by davegson on June 16, 2020 | 2 comments]
https://news.ycombinator.com/submitted?id=davegson
I used Little Snitch on Mac a few years ago and liked it, though I wasn't a fan of how (necessarily) deep it had to be in the OS to work. It felt like one of those things where, the moment you have any kind of network connectivity issue, it's the first thing you need to disable to troubleshoot because it's the weirdest thing you're doing.
I guess what I'd really like is a middleware box or something that I could put on my home network, but would then still give the same user experience as the normal app. I don't want to have to log into some web interface and manually add firewall rules after I find something not working. I like the pop-ups that tell you exactly when you're trying to do something that is blocked, and allow you to either add a rule or not.
I'm probably straddling some gray area between consumer-focused and enterprise-focused feature sets, but it would be neat.
I am the same, used Little Snitch for a few years back in the late 2000s, I think like 2010 until a few years back when I moved fulltime to Linux. Back then, my parents had an iMac and I was the designated "IT" person to keep it running efficiently. My siblings had a bad habit of installing games and hack software on it for their games. I ended up purchasing a license and after the first few hours/days of configuring allow/block lists, it worked pretty well. It earned the label of "Little B*ch" from them since it would stop their gaming hacking apps from connecting and wrecking havoc. Eventually I learned to keep them on a standard user account and separate admin for installing software.
Long story you didn't ask for. Like I said, I haven't used Little Snitch in a while. I'll give this a whirl this weekend. What I have done over the past few years is run AdGuard Home on a min home server. This has helped keep ads undercontrol in our hoursehold and I have an easy "turn off adguard for 10 mins" in homeassistant for the wife so she can do some shopping online since it can occasionally break some sites, but overall they tolerate adguard and think it's a good middle ground. I have a few block lists, nothing too crazy or strict to avoid breaking most sites. On the desktops/laptops, they all run FireFox w uBlock origin.
How deep it was in the OS was exactly what I liked about it. I only wished it were open source so I know what exactly is happening with that level of access.
I’ve also wanted something like this. The challenge is with an external appliance you lose awareness of which process is initiating the request.
This is solvable to some degree but requires varying degrees of new complexity depending how smooth of a user experience you’re aiming for.
Just tried it on my laptop. Unfortunately, my laptop got extremely hot about 10 seconds after installation. The resource monitor showed that it was eating up all of my laptop's CPU. I panically stopped the service and uninstalled it before I could even open the web UI. It was a really poor first impression.
How does it compare to opensnitch? https://github.com/evilsocket/opensnitch
I just tried littlesnitch and it did not resolve very many ips to domains, which is pretty basic. It also failed to identify most processes, and they were grouped under "Not Identified". It appears these are known limitations of the Linux version [1]. So for that alone I need to stick with opensnitch.
[1] "Little Snitch for Linux is built for privacy, not security, and that distinction matters. The macOS version can make stronger guarantees because it can have more complexity. On Linux, the foundation is eBPF, which is powerful but bounded: it has strict limits on storage size and program complexity. Under heavy traffic, cache tables can overflow, which makes it impossible to reliably tie every network packet to a process or a DNS name. And reconstructing which hostname was originally looked up for a given IP address requires heuristics rather than certainty. The macOS version uses deep packet inspection to do this more reliably. That's not an option here." -- from https://obdev.at/products/littlesnitch-linux/index.html
Regarding unidentified processes: Little Snitch daemon must have been running when the process started in order to identify it reliably. It's best to reboot after installation so that Little Snitch starts before everything else. I should probably note this somewhere.
And regarding failed reverse DNS names: Little Snitch is sniffing DNS lookups. If lookups are encrypted, there is little it can do. We usually recommend DNS encryption at the systemd layer, not at app layer. This way we can see lookups on 127.0.0.53 and the actual lookup sent out is still encrypted.
Also, it's currently only sniffing UDP lookups, not TCP. The eBPF part is already very close to the complexity limits (700k instructions of allowed 1M) and adding TCP parsing would exceed this limit. It should be possible to forbid TCP port 53 with a rule, though. Some complex DNS lookups will fail, but routine things should still work.
The thing is, 127.0.0.53 is a fallback. The real default upstream is nss_resolve, which talks to systemd-resolved via non-DNS protocol on a UNIX-domain socket. Ubuntu disabled this in favor of the less-featured fallback. If you insist on sniffing DNS, you need to add instructions to disable the native nss_resolve module by not including it in /etc/nsswitch.conf.
If I don't know who my machine is talking to, the information is not very useful. So there needs to be a fallback on some level.
Perhaps there should be a mode where littlesnitch just does its own lookup using the system-configured rDNS, for example from the ui or for specific processes, etc? It should be cached if it is a recent lookup, so minimal performance implications; and offloaded to the system rDNS resolver, so minimal instruction set.
Not all "hostname lookups" by applications happen over DNS (or the DNS is done by something like systemd-resolved, which is often using encrypted lookups), so in many cases, depending on NSS configuration (e.g. 'file', 'resolve', 'db', 'nis', 'mymachines', 'libvirt', 'winbind', ...) this would never work?
I'm curious, why not do things like the DNS look-up from userspace?
I wonder why LS can't be given access to systemd resolved stub resolver to get all my DNS lookups.
I guess that makes sense, since it's pretty new. OpenSnitch is great software in terms of functionality but I find the UI lacking. If LittleSnitch can keep the same functionality, while improving the UI, I'm switching. My other current concern here is that the LittleSnitch UI is just a Webview and I think it would be much better if there was a native option (ideally GTK-based for me, but Qt would also be acceptable). Webviews are slow and full of bloat.
Is there any DNS based software to do block/allow? Kinda lika what's present in CiliumNetworkPolicies in Kubernetes networking?
Yes, PiHole is the most common, but malware can easily bypass that using shared domains, P2P or IP addresses directly.
Use a filtering proxy instead and no gateway / route to the internet.
1) Dnsmasq, you don't need the whole PiHole for that.
2) You're advising security through obscurity instead of a network namespace + firewall.
You mean like PiHole or AdGuard?
OpenSnitch (+ block lists) ;)
or DNS stubs with filtering capabilities.
Not sure, I was wondering the same, opensnitch is what I have installed but its not on currently, I probably got tired of it for whatever reason.
"I researched a bit, found OpenSnitch, several command line tools, and various security systems built for servers. None of these gave me what I wanted: see which process is making which connections, and in the best case deny with a single click." https://obdev.at/blog/little-snitch-for-linux/
I've used OpenSnitch for years, and while LittleSnitch definitely has a better UI for showing which process is making which connections over time, OpenSnitch does a pretty good job here. I get a modal popup when a program that hasn't made a connection tries to make a connection, and I can either allow/deny in one click, or further customize the rule e.g. allowing ntpd to connect, but only to pool.ntp.org on port 123.
Where LittleSnitch is definitely ahead is showing process connections over time after said process has been allowed.
When I looked at OpenSnitch (years ago), it didn't support running headless on a server. Am I mistaken about this, or has it changed?
You can run daemons on several nodes (different machines) and view them all through a central ui, it is pretty cool.
The UI is a separate package. Though you might just configure the firewall yourself at that point.
It is free, no subscription at all and truly open source.
As software should be.
how should maintainer make money?
Personally I'd be fine with a commercial license with source available here... the issue isn't the price, it's the fact that you're asked to MITM every network connection you make under the control of a binary blob.
I think it's fair to ask that a developer choosing to build a thing that requires that kind of access should be expected to err on the side of transparency.
I've happily been a paid user on macOS for years, I would guess the number of paid users there was able to fund the Linux development.
You mean “how can I donate?”
https://github.com/evilsocket/opensnitch?tab=readme-ov-file#...
So... what if the maker can't make it on donations only?
Then development will stop and users don't have the software anymore.
If users consider this software important they should donate so they can keep using it.
How exactly is this different from payed software?
There is a ton of software that lives on because it matters to the developer(s). I know "but mah monetization" is huge on this forum but it's not an all encompassing rule and it does not completely reflect the existing reality.
Strong disagree on this stance. You want to use the software? Cool, pay for it. Need access to source? It's on github, go nuts. Want to change it? Sure, feel free, but whoever uses it should pay the original developer. You can even charge extra for your modifications. Don't like the terms? Too bad - feel free to rewrite from scratch.
FOSS simply isn't sustainable if you want to make a living out of it. It protects a lot of user freedoms - even those that don't actually matter to users that much - at the expense of the rights of developers. There are a lot of ways that developers could be paid and users would still be protected (have access to source and the right to modify). The only ones benefitting from the current situation are BigTech.
/rant
Who are we to dictate terms to or divine the intentions of someone who releases software with say the MIT license? It might sound surprising but a lot of developers just want to share their work altruistically. There are some you couldn't pay if you wanted to. It's all voluntary.
> FOSS simply isn't sustainable if you want to make a living out of it.
This is probably true enough. Yet there are a million open source projects that existed, some for decades. There has go to be another way and another motivation.
> even those that don't actually matter to users that much - at the expense of the rights of developers
I would assume those developers would use a different license or even create their own terms.
> The only ones benefitting from the current situation are BigTech.
Paying the original developers will not change this. Big tech is big. They take whatever they can, sometimes killing the original project in the process. Perhaps a license like GPL is the solution to that particular problem.
I don't mean to come off snarky. I do agree with a lot of the things that you're saying but I see the free software movement as a completely voluntary and human thing. You could not get rid of it if you wanted. Paying for it is an auxiliary thing and concentrates too much on the wrong thing IMO. A lot of free software developers are already gainfully employed, some are millionaires. Yes some are struggling but then they are still voluntarily sharing their work with the whole world. That must mean they have their valid reasons for doing so.
The developer isn’t accepting a job offer to develop it, they’re accepting donations. That’s literally how the software devs for Opensnitch choose to receive payment.
Hunt, gather.
There was also toolmaker to support the hunter and gatherer… so… back to square one.
open source / free software is not necessarily free as in free beer. You can sell GPL software.
Wow. I have used Little Snitch on Mac for years, love this!
If anyone from obdev is reading, please give us a way to pay for it, even if it stays free :), I'd love to support development and would happily pay something between the price of Little Snitch and Little Snitch Mini.
Anyway, thanks a lot!
I used to use a Windows firewall which basically hijacked a bunch of WinAPI calls and let me approve/deny every request. Trying to be a good secure boy I ran this setup for a while but it was exhausting. Every single action needed dozens of approval windows. After a while I removed the software. I reckon it is good situationally though, trying out a new program for first time (that isn't risky enough for a VM or sandbox), might be good to turn on a tool like this.
There was a similar Show HN from 3 weeks ago. https://news.ycombinator.com/item?id=47387443 (open source too) - and there is a live window from all the machines in the swarm. https://dialtoneapp.com/explore - but only 2 so far. Maybe LittleSnitch can generate more data than this? Could end up an immune system for bad actors.
Anything new to get much better performance from low-spec machines that is idiot-proof is a game-changer.
Congrats to Linux users on getting a great tool from a quality development shop. Objective Development is one of our (Mac users) exemplars for attention to detail and fit & finish.
Congrats to Objective Development for expanding their well-loved tool to a new platform. You guys rock.
>attention to detail
Why does LittleSnitch (Mac) pre-resolve IP addresses, before user presses Accept/Deny?
IMHO DNS queries shouldn't initiate without user input.
Little Snitch is bound to the API provided by Apple. The NEFilterDataProvider API calls `handleNewFlow()` only after sending out the first IP packet.
Version 6 added DNS encryption and in principle we could filter lookups (similar to PiHole) at this level. That brings other issues, though: This filter is system-wide, so process-specific rules (and overrides) would not work. And results can be cached by mDNSResponder. So when a blocklist causes an issue, you may not be able to fix it by simply disabling the blocklist. But it's still something we consider.
>in principle we could filter lookups
I've been telling people about ya'll's DNS leaks for over a decade [3] — glad to finally hear back — most people won't believe me [0] until this flaw is demonstrated on their specific machine (easy enough). Those already using LittleSnitch will then typically set up better filtering (e.g. DNS white/blacklist, PiHole, et.alius).
And until the behavior is fixed, I will keep spreading the good word. Does the Linux version have this same flaw (i.e. backend requirements similar to Mac initial IP leak)?
----
A very neat product (LittleSnitch), but I stopped using it solely for above reason [1]. IMHO, this flaw should be better documented in your installer/docs.
[0] e.g. they'll lament "there is no way the developer would allow that sort of leak/behavior!" Their denial is a helluvadrug
[1] I had a 5-user site license, IIRC. Shortly after purchasing, I discovered above leakage so stopped using entirely [v3 user 33TEWP20B0-724KY-5XE522FEAC [2]]
[2] Go ahead and blacklist/cancel the above registration (it's a manyyearsold version, barely used) – my current mailing address is in my user profile (no longer use email/phone). Would love to help/feedback to make your product better. Would also love a refund (all these years later, on principle)
[3] e.g: <https://news.ycombinator.com/item?id=35363343> (/hn/2023)
Question for devs, not me.
Did the "attention to detail" phrase come from devs or you?
From me. OD is a great dev firm. Do you understand my statement?
>OD is a great dev firm
Please see my response to OD [I presume /u/littlesnitch is OD representative]. Nobody is disputing their "greatness" — I'm just criticizing a flaw in their approach to domain name filtering.
Hopefully OD will refund my original license (unused for many many many years, after I discovered this flaw). That would be good, in principle; good business. Hopefully OD will be more forthcoming in this vulnerability (or better disclose it) — or better yet: fix the unbelievable behavior.
Do you understand that you can't redirect the question addressed to you to the devs if that question questions your own statement by pointing out that some important details are not attended to?
Probably should throw it out there that I'm building something inspired by littleSnitch for windows. Currently a bit stealthy about it. But when I crowd source the funding for a code signing cert I'll get it out there. Lots of inspiration from LittleSnitch, in spirit if not actual code.
I'd be curious to hear additional details if you can share - got a timeline, or somewhere I can enter my email address for updates? I'd love to alpha/beta test if you're looking for testers.
I've been a GlassWire user for years, which partially fills the role of LS, but not very well. Aside from the many performance issues I've seen, it's missing a lot of LS essentials. To be fair, I think the focus of GlassWire is more about visualizing traffic on your Windows computer, but I definitely believe there is a need for better Windows network software for power users.
It's a custom WFP driver. No timeline yet..
If you or I guess anyone is curious sereno[hyphen]alpha[dot]ramble[thenumberoftechn9ne'sfavoriterum]@passinbox.com
The irony of having to ask AI to figure that out… we’ve come full circle.
Just reached out (I think )
Awesome. I always felt Linux was missing a per-application firewall. I didn't dig much into it but at least iptables didn't have rules for that when I looked.
Incredible. LittleSnitch is must-have for macOS and trying to get equivalent functionality on Linux was painful. So very happy to see this, and very happy to give the developers at Objective Development my money.
In linux, I trust most distro apps to run with network access without any sort of firewall. And for apps from internet, just put them in bubblewrap or run with flatpak without access to homedir, network, audio, video etc. depending on program.
LittleSnitch for Mac is a good looking app.
I always thought that ugly UIs on Linux are because of good designers do not intersect well with programming enthusiasts.
But looking how ugly same app looks on Linux, I’m starting to think it could be a technical limitation. Can someone elaborate?
It just depends on the UI frameworks available to developers and their interest in building something good-looking. Different UI frameworks are available for different platforms, and there are only a few good ones that are cross-platform. Qt and GTK are pretty common for linux apps and typically don't look great.
LittleSnitch doesn't tattle on itself phoning home.
Is that true? If so, that’s not a good sign. I remember how impressed I was by ZoneAlarm in the early 2000s asking permission for itself to connect to the Internet, using the exact same dialogue it presented for any other program, with no dark patterns suggesting that the user should give preferential treatment to it.
Doesn't seem to be, I can see LittleSnitch itself connecting to yoyo.org and obdev.at. GP may be referencing a past bug, either in LittleSnitch or macOS.
If it connects to yoyo.org, you have subscribed to Peter Lowe's blocklist and Little Snitch is trying to update the list from there.
I have, yes. Didn't bother to check the domains, just wanted to say they were visible.
It does… and if it didn’t it would be trivial to prove.
Any proofs for this claim?
I'm so surprised that so few people have heard of Portmaster, it's been around for years and runs on Linux (and Windows if you must). And if you don't need traffic history it's free.
portmaster is the tool i use for upgrading installed ports on freebsd since… like… olden times.
I’ve been researching the “best” way to build a little outbound network proxy to replace credential placeholders with the real secrets. Since this is designed to secure agents workloads, I figured I might as well add some domain blocking, and other outbound network controls, so I’ve been looking for Little-snitch-like apps to build on. I’ve been surprised to find that there aren’t a ton of open source “filter and potentially block all outbound connections according to rules”. This seems like the sort of thing that would be in a lot of Linux admins’ toolkit, but I guess not! I appreciate these guys building and releasing this.
Something almost no firewalls get right is pausing connections (NOT rejecting them) until I've decided whether to allow or not. The only firewalls I've seen do this are Little Snitch for Mac, and Portmaster for Windows (before they made it adware / started locking existing local features behind the subscription).
Firewalls don't do this because they are built at the wrong layer to do proper pending calls. It's too narrow of a design space for most firewalls to care.
True, most firewalls aren't built to pause for user input. But then again, that's why almost no firewall software is suitable for this user experience.
I use Portmaster (on Linux) and I have never seen ads (either in the app or apps that get their DNS from Portmaster) on it. About the only thing I saw different between the free version and the base level paid for version was traffic history and weekly reports (and badges on Discord if that's your kind of thing).
Both used to be free. And you may not consider it advertising when unavailable features exist in the free UI just to tell you they're paid, but I do. Especially when they used to be free.
OpenSnitch seems to do this just fine? Unless I’m misunderstanding your point. Connections seem to just block until I take an action on the dialog. Now, if an application itself has specified a short timeout (looking at you, NodeJS-based stuff), that obviously doesn’t help. But for most software it works great.
>> The macOS version uses deep packet inspection to do this more reliably. That's not an option here.
I thought it would be easier to do DPI on Linux than macOS. No???
eBPF is very limited in the code complexity you can achieve. DPI on QUIC, for example, needs a lot of cryptography. That's simply not possible in eBPF. DPI on ordinary TLS still requires that you collect enough network packets to get the name, hold them back until you have a decision and then re-inject them. Holding back packets is not even possible at the layer where we intercept. And even if we find a layer to do this, it adds enough complexity that we no longer pass the verifier.
Yeah I thought that was one of the primary use cases of eBPF. Not an expert though, just read about some of these things.
Does it leak your IP like the Mac version?
https://news.ycombinator.com/item?id=35363343
> Little Snitch for Linux is not a security tool.
Maybe not?
> Its focus is privacy:
Or maybe yes?
You are referring to the TCP three way handshake problem here. The macOS version is bound by the API provided by Apple: We get the API call for filtering only after the three way handshake has started.
The Linux version is limited in complexity. It has to decide immediately. This has the consequence that no packet leaves the machine if the connection is denied, but on the other hand it means that it's easier to trick. The macOS version can inspect the first packet sent (deep packet inspection) to find the remote host name in TLS headers. The Linux version relies on heuristics: The most recent lookup seen which returned the IP address determines the name. This part is Open Source and you can inspect the algorithm.
I use Lulu on my mac. Is it good enough (compared to LittleSnitch)?
Haven’t tried LittleSnitch, but from what I see it’s on par as far as features go. LuLu’s UI could use some improvements, but otherwise it’s perfectly fine for the job.
I would say it's better.
I'm glad people are building stuff for Linux, but the people who actually want something like this have likely already been using Opensnitch for years. I'm certainly not going to spend $60 for something that has been doing the job for free.
From the related blog post[0]:
> You can find Little Snitch for Linux here[1]. It is free, and it will stay that way.
[0]: https://obdev.at/blog/little-snitch-for-linux/
[1]: https://obdev.at/products/littlesnitch-linux
I know it sounds crazy at this point, but with popular YouTubers switching to Linux, gamers overall well-aware of Steam on Linux advantages and switching as well, plus popular software like LittleSnitch getting ported, 2026 can without irony be named as Year of Linux Desktop, right?
The year of the Linux Desktop will always be $CURRENT_YEAR + 1
To me, the year's in the past. I haven't touched Windows since 2017, and nothing bad happened to me.
But you're right, I guess for some people, there will already be a good reason not to use Linux.
I did the switch in 2013 and haven't missed it. For games I ran vga_passthrough and later VFIO and others until pretty recently (I think right after covid I switched to steam directly on linux)
The year of the Linux Desktop will be powered by fusion.
What do you call a fallacy where it is implied that the future will be like the past?
Problem of induction: https://en.wikipedia.org/wiki/Problem_of_induction
Reminds me about schools of thought on rates of change:
linear % change implies exponential change in absolute terms
Maybe similar to boy who cried wolf?
"The future aint what it used to be."
> 2026 can without irony be named as Year of Linux Desktop, right?
For whom? Average desktop users? Average users don't know what LittleSnitch is, let alone calling it "popular software."
For Linux desktop users. A bit of tongue-in-cheek but that's pretty much the argument that I've heard in some circles ("it works for us and not going away anytime soon - why waste time convincing others?").
That's some beautiful, text-book straw man!
?
So for whom?
I think there is a lot of talk (and this is good), but very little action. Market share is still incredibly low for LNX. I believe only a small subset of people actually attempt the jump from WIN to LNX (since most just want to play their games and run their programs without hassle) and then quickly realize that its tougher than they anticipated and swiftly return to WIN.
This is true, but also the original comment still stands: Linux desktop usage outside developers was so low that it was barely worth mentioning before, so even a small uptick like this is a serious change, and it's how bigger changes start.
I definitely don't think it's even the likely outcome, but for Linux to get serious traction this is how it has to start: power users but not the traditional developer crowd start actually moving, and in doing so produce the guides, experience, word of mouth, and motivation that normal people need to do so, alongside the institutional support from Valve to actually fix the bugs and issues.
It remains to be seen if a critical mass will find it usable long-term, but if it were to happen, this is how it would look at the start, and Microsoft are certainly doing their best to push people away right now, although I suspect the real winner is more likely to be Apple with the Macbook Neo sucking up more of the lower end.
> Microsoft are certainly doing their best to push people away right now
According to a speculative blog post by Eric S. Raymond in September 2020, Microsoft is literally moving towards replacing Windows' internals with Linux. Unfortunately, that post is now unreachable, but searching for "eric raymond article about windows being replaced with a linux kernel" finds many third-party references to it and summaries of it.
Last phase of the desktop wars? by Eric Raymond: https://esr.ibiblio.org/?p=8764
5% on the steam survey though. The jump isn't quite as big from previous years as it seems as they did some corrections to the statistics this year, but 5% is nothing to sneeze at.
Exactly! Me personally in 2010 would never though about the time when one on every 20 gamers will be Linux user. That is huge IMHO.
I wouldn't be too exited. Statistics like this are very problematic.
For example, I have Steam installed on my Macbook pro and I occasionally play a single very simple game there. Does that make me a macOS gamer? of course not. The vast majority of games I want to play don't work on macOS.
I suspect that most of those 5% are just Linux users who have steam installed and play a small amount of games. Some probably just installed it to check what's available and don't play anything.
Everyone I know who is a "serious" gamer, as in exited about upcoming releases of AAA games is using Windows.
Indeed. The bigger problem is also that consistently the most played games are multiplayer competitive titles with anti-cheat software that is only written for Windows (and sometimes MacOS). I suppose this issue will solve itself, once enough people start playing on Linux. Then developers will be forced to support that too in order to not lose too much of their player base, but we are still a far cry from this threshold.
That would mean that it still would be around 0,5%. If you want to split the hair probably 4,5% of this 5% is Steam Deck.
As someone who did make the jump, it was actually a lot easier than I anticipated. I encourage others to do the same. The only games I can't play are some AAA multiplayer games I wasn't particularly interested in anyways.
I think for people who are browsing this site, it will certainly be easier than expected. For the average person, most likely not.
What’s with the weird abbreviations?
He is saving 4 keystrokes out of ~400 by typing LNX instead of Linux.
But holding the shift key makes up for it, so seems like a bad strategy
You are overthinking it. It is neither a strategy nor keystroke saving (although technically with shift its 4 keystrokes as opposed to 5 for Linux and quite a few saved for Windows). I just typed that without thinking probably because it looks better and reads a bit easier (subjectively).
I hope more and more folks who want gaming computers realize how turnkey bazzite is, especially if you’re team red. It’s pretty remarkable
2026 is the year of the linux phone. We need to embrace that the year of the linux desktop (2025) was successful.
According to latest Steam stats[0], Linux hit > 5% for the first time ever, so definitely successful (to some degree).
[0] https://store.steampowered.com/hwsurvey/steam-hardware-softw...
I wish. I'm tired of not owning my phone. But I don't see a push being done to get a proper Linux phone
Sadly year of the linux phone feels like it's getting farther away.
What does "the year of the Linux phone" mean when half the phones already run Linux?
Android/Google does not fulfill the spirit of that. Yes it’s technically Linux, but it’s not what one expects from a Linux experience. We all know this, we all know Linux is under the hood, but “Linux phone” is basically shorthand for more user control, more open source aspects, more secure/private, and far away from companies like Google/apple/etc. Android phones do not fill that request even with graphene and such. Google still has too much control.
And the other half run BSD
kde linux may make it happen. that and command line agents that help people fix their systems.
It’s definitely what converted me (steamOS first real experience, then mint, pop, and now bazzite)
Also unrelated, but more linux gamers proves my personal observation that on the spectrum of computer literacy gamers are just below powerusers and programmers. We see more less technical people migrate over to Linux gradually and now it's gamers turn. Well, that's kind of obvious for everybody except Microsoft apparently.
does wifi work yet? last year it didnt for me
Wifi has been working out of the box for close to 20 years now. On some computers with old Broadcom cards, you have to enable non-free drivers. What model are you using?
WiFi works fine if there are drivers for whatever WiFi chip you have.
Unfortunately there are no standards for OS to talk to WiFi devices like exist for many other types of hardware, so it’s not possible to make generic drivers.
Wifi and Bluetooth are pretty decent now. As far as I can tell the biggest blockers are:
* Laptop battery life. Still in the "it's fine; I get 5 hours!" stage.
* Wayland & graphics. It's still a mess. Getting there though. Probably will be ok in about 5 years I'd guess.
* RAM management. I don't know why nobody cares about this but when Mac or Windows run low of RAM I don't even notice. With Linux it either hard freezes and reboots, or hard freezes for like 5 minutes and then kills a completely random program. How is that ok? My solution here was to upgrade both my computers to 128 GB of RAM, but that isn't really a viable option today!
* Generally bugginess. Both KDE and Gnome are just not as rock solid as Windows 11. I know I'll get downvoted for this but I haven't experienced a single crash on Windows 11 (and no ads or bloatware because I did research and used the LTSC edition). In KDE, much as I love it, the taskbar crashes regularly and I cannot make head nor tail of the completely random order it wants to put windows in. You can't even drag them into a sensible order. Gnome was not much better.
Still KDE is a lot better now than it was in the kidney bean days so I reckon in another 5 years it will probably be pretty solid too.
Did you forget your WiFi password?
yes
No.
I've been using Simplewall on Windows for a while but I think it's not maintained anymore. Need to find an alternative
Fort Firewall is my tool of choice. Each connection requires explicit approval.
same with simplewall
Unfortunately it significantly impacts battery life, at least at my tests.
>The daemon (littlesnitch --daemon) is proprietary, but free to use and redistribute.
Worth noting that it is closed source. Would be worth contributing patches to OpenSnitch to bring it up to parity with Little Snitch.
https://github.com/evilsocket/opensnitch
Thanks for sharing Open Snitch
As articulated in the author's own blog post:
https://obdev.at/blog/little-snitch-for-linux/
The core issue is simple and uncomfortable: through automatic updates, a vendor can run any code, with any privileges, on your machine, at any time.
-----
If the author is serious about this, then they should make their own program completely open source, and make builds bit-for-bit reproducible.
For all I know, the proprietary Little Snitch daemon, or even the binaries they're distributing for the open source components, contain backdoors that can be remotely activated to run any code, with any privileges, on your machine, at any time.
This is correct, of course. But I currently can't make the entire project Open Source. My other option would be to keep it completely private (wrote it mostly for myself in the first place).
I think it's still better to make it public and only partially Open Source so that some people can benefit from it. If you don't trust us, that's completely reasonable, just don't install it.
One person's (not my) take on why to skip this: https://the.unknown-universe.co.uk/privacy-security/little-s...
TL;DR it's closed source and there's open source alternatives.
Also see Safing Port master:
https://safing.io/
Related - I'm working on launching Watch.ly[0] (human-in-the-loop for remotely approving network and file system access for agents) in the next week or so. It works similarly, via eBPF (although we can also fall back to NFQUEUE). Supporting 5.x+ linux kernels[1], osx, and windows.
Did not know about LittleSnitch, will definitely check it out.
[0] https://watch.ly/
[1] https://app.watch.ly/status/
Will there ever be anything like Comodo Firewall's HIPS firewall on Linux [0]? I remember when firewalls like ZoneAlarm could detect keyboard hooks from keyloggers and such. Comodo Firewall has had this for over a decade, but unfortunately they are not free anymore. For how open Linux is, it surprises me you can't handle things apps are doing on an alert by alert basis, and not just network permissions. Firewalls used to detect DLL injections, apps creating script files to run, adding stuff to start up. Now it seems firewalls only means network detection.
[0] https://help.comodo.com/uploads/Comodo%20Internet%20Security...
How does this work with WSL2? Will it monitor windows traffic as well?
Old bottle with new lable, but good to keep eye on interfaces
Low-effort take: can't you just run ss -tulpn repeatedly and parse the output?
> The macOS version uses deep packet inspection to do this more reliably. That's not an option here.
Isn't MacOS just *nix under the hood? Genuinely curious about this difference.
An operating system is roughly broken into three parts: the kernel, the core system tools, and the shell (the desktop environment and/or the CLI shell). Linux: Linux kernel, GNU coreutils (usually), KDE/Gnome/etc + CLI shells. macOS: XNU, BSD userland + launchd/etc, Aqua/Cocoa. Windows: NT kernel, Win32/WinRT/etc, Windows Shell.
The systems LittleSnitch uses to do packet inspection are very much OS-specific. There's no generic standard for doing high-performance packet inspection. XNU and Linux are *very* different kernels. Linus Torvalds built Linux from scratch as a monolithic kernel because he wanted a Unix-like OS that wasn't encumbered. XNU is based on the Mach microkernel though XNU is a hybrid or monolithic kernel, not a microkernel. The point is, they have very different heritage and very different systems for... well pretty much everything. So "just *nix under the hood" is kind of true but also completely besides the point as far as packet inspection goes. And even then, while there are a lot of similarities between the core system tools of Linux and macOS, they're still quite different and unless you're limiting yourself to POSIX-standard interfaces (which are only a fraction of the system), you're not going to be able to use the same code on both systems.
More the opposite. macOS is a veneer of nix, but underneath it is the XNU microkernel. Lots more nuance since Apple took over and added a lot of their own performance and API improvements to
From what I understand, macOS uses weird kernel implementation, which is almost open source, but not 100%
You're correct, but for a bit more context: The macOS kernel is XNU, which is derived from/based on the Mach kernel, but heavily modified. The kernel itself is open source but some drivers/kernel extensions are not so it's not actually usable (unless you provide your own implementations of those).
BSD family with fewer GPL parts each year
Ohhh interesting. Little snitch is one of 2 apps I miss from when the Mac was my daily driver. The other app was pixelmator
Does little snitch and similar software work against solutions like Paqet?
https://github.com/hanselime/paqet
On macOS, it requires access to /dev/bpf. That's why we added filter rules for bpf there.
On Linux, we intercept at a level where packets already have an Ethernet header. I hope that Paqet injects before* this layer, but only a test can give the proof.
I hope they provide a binary without dynamic libraries so that we can use this on nixos as well
> Compatible with Linux kernel 6.12 or higher
I know everyone today is used to upgrading every 5 seconds, but some of us are stuck on old software. For example, my Linux machine keeps rebooting and sucks up power in suspend mode because of buggy drivers in 6.12+, so I'm stuck on 6.8. (which is extra annoying because I bought this laptop for its Linux hardware support...)
In theory, it could be possible to get the requirement down to 5.17, but I don't get around the verifier constraints on pre 6.12 kernels. Maybe somebody who is more experienced with eBPF and the verifier can help. This part is Open Source and you can replace it.
Does anyone know how the blocking functionality works? I worked on some eBPF code a few years ago (when BTF/CO-RE was new), and while it was powerful, you couldn't just write to memory, or make function calls in the kernel.
Is there a userland component that's using something like iptables? (Can iptables block traffic originating from/destined to a specific process nowadays?)
eBPF is extended in every kernel version. There is a layer where you get network packets and return a verdict. Little Snitch uses this type of eBPF function. You can look at the sources on Github.
Back when I was still using macOS I loved Little Snitch and was a paying customer. And I agree nothing on Linux comes close. Would it be technically feasible to also provide this as a Flatpak to support immutable distros like Bazzite?
I’m not aware of flatpaks specifically having th capability to run system software, daemons, etc. Some other immutable packaging formats should be able to (systemd-sysext at least, and snap iirc).
As far as I can tell, Flatpak does not allow a daemon running as root early during system boot.
Giving it a shot right now. Very easy setup, intuitive UI, but a lot of requests' processes are not identified (while they could easily be identified, as they belong to the browser that has some, but less, identified calls)
Little Snitch must be running when the process starts in order to identify it correctly. You get less "Not Identified" if you run it for a while, or you should get none if you reboot and Little Snitch can start before everything else.
I would love to fix this requirement, but have not found a way yet.
FYI: It's an Austrian company behind that software.
I really want Little Snitch for iOS.
Hopefully Apple makes the necessary frameworks available on iOS in general. Not only for supervised devices.
Same.
They are still restricting iCloud Private Relay to Safari for the most part. iOS is really wanting for privacy improvements to close the gap between marketing and reality.
Fun fact: iOS lets developers spy on when you _dismiss_ notifications:
https://developer.apple.com/documentation/usernotifications/...
Ever instantly angry-swipe-to-clear a DM notification soon as it hits your lockscreen from someone who upset you? Zuck knew y'all had beef.
Clear notifications before bed and in the morning? All those companies could know a bit more about your routine than you would've otherwise revealed if weren't in the habit of using those apps at those times.
--
The kinds of tiny things that would be pretty inconsequential on their own but that you figure maybe the Apple tax would help you avoid.
(edited with additions)
I wish applications like this could coordinate with upstream firewall like opnsense
> One thing to be aware of: the .lsrules format from Little Snitch on macOS is not compatible with the Linux version.
Why?
Just because I did not port the parser for it to Rust. And I thought that the lsrules format is rare for blocklists. If there is popular demand, we can add it.
You should add this feature.
Probably because it relies on eBPF rules on Linux?
So if this is free to use on linux, what is to stop someone from doing what Colima did to Docker? Aka make a tiny Linux VM on MacOS and package Little Snitch within that?
It barely has any of the features of the MacOS version, there is no shortage of cracks for Little Snitch, and there is Lulu. Other than that, I am not sure.
I don't think it'll have access to the macOS connections, and certainly cannot act at the kernel-supported level as a firewall on the Mac side.
Little Snitch requires packet inspection. If you ran it in a Linux VM, it will inspect packets within the VM. So... kind of useless for monitoring connections on the host.
I'd like to point out it uses very little memory, barely 33MB here. That's impressive!
> For keeping tabs on what your software is up to and blocking legitimate software from phoning home, Little Snitch for Linux works well. For hardening a system against a determined adversary, it's not the right tool.
What would be the right tool to harden in a similar way to little snitch on mac? Meaning intercepting any connection and whitelisting them reliably.
cool to see eBPF used for a desktop firewall instead of just ddos packet dropping. the note about bpf map overflows is super relatable, dealing with that on bare-metal is a pain.
my question is... if the tracking maps fill up completely, does the daemon fail-open or fail-closed?
There is currently no treatment of errors because I would not know how to handle them anyway. There are two tables which can overflow affecting the filter: the table of open flows and the table of recent DNS lookups. The table of flows just fills up, meaning that we cannot store state about new flows. Without state, we can't attribute a process to them and end up evaluating rules on each packet. I guess that blocklists would still work, but more specific rules would not be applied (and the default decision would be taken, whatever you have configured).
The DNS lookups, on the other hand, are LRU. If the table overflows too soon, we won't be able to derive names for IP addresses and name-based rules would fail.
doesn't work on arch (btw)
Also from [0].
> You can find Little Snitch for Linux here. It is free, and it will stay that way.
Don't worry, the authors know that there's no point in charging Linux users. Unlike Mac users.
So you might as well make it $0 and the (Linux) crowd goes wild that they don't need to pay a cent.
However...
> I researched a bit, found OpenSnitch, several command line tools, and various security systems built for servers. None of these gave me what I wanted: see which process is making which connections, and in the best case deny with a single click.
OpenSnitch is open source. You don't need to trust it as you can see the code yourself. Little Snitch on the other hand, is completely closed source.
Do you still trust them not to do self-reporting or phoning home, even though it is $0 and closed source?
[0] https://obdev.at/blog/little-snitch-for-linux/
Two of the three components of LittleSnitch for Linux are open source. The eBPF (kernel portion) and UI are fully open source.
> Do you still trust them not to do self-reporting or phoning home, even though it is $0 and closed source?
If you trust Little Snitch on Mac, then yes.
They've been in business for over 20 years. They're not going to blow their entire business and reputation for a few Linux users.
Yep, I trust the obdev.at / Snitch guys.
I do wonder however, are they sufficiently careful about their processes and own machines to avoid a supply chain attack completely.
They must be a target for the various hacking groups out there.
We have not detected a targeted attack yet. On the Mac side, we are safe: No dependencies on any third party libraries. Only Apple.
On the Linux side, there is no single big vendor such as Apple who provides all the necessary libraries. I have tried to choose reputable sources from crates.io only, but to be honest, I don't know a secure solution to the problem.
This comment seems a bit confused.
A supply chain attack doesn't directly attack an end developer but rather a supplier of the developer. So who or what is the supplier in this case?
They don't build their own machines or write their compilers or write their own crpyto code or ... so many other things.
> They don't build their own machines or write their compilers or write their own crpyto code or ... so many other things.
An attack on any of these things has nothing specifically to do with the developers of Little Snitch and would have vastly more widespread and important effects.
Why would you even be talking about Little Snitch if a compiler were compromised?!? Your paranoia here is bizarrely narrow. Little Snitch would be the least of our problems in that case.
Their copy of the compiler. Just an example. ¯\_(ツ)_/¯
> Their copy of the compiler.
This doesn't even make sense. You have no examples.
That seems... not correct?
The comment was asking about preventing a compromised supplier for the developers.
A supply chain attack can be anywhere in the supply chain to the target. If I, the end user, am the target, then a supply chain attack compromising the developer of LittleSnitch is effective.
I may then be a conduit to compromising other software or components, and would both I and LittleSnitch would be part of the supply chain that could be attacked targeting them.
> If I, the end user, am the target
You're not a target, anonymous rando.
Many supply chain attacks aim to run malware on the end-users machine to harvest authentication tokens, etc. So pretty much everyone here who is a developer is the target.
> So pretty much everyone here who is a developer is the target.
Are you going to have this same discussion about every piece of software every mentioned on Hacker News? Why are we having it for Little Snitch specifically?
This seems pedantic and I think you know what they’re questioning and why.
If they trust the devs why would they not trust them to not yolo deploy new versions?
because a company worthy of trust doesn't yolo their versions. a company that does yolo versions is not trustworthy.
Because it might not be the developers doing the deploying, but a malicious actor?
> I think you know what they’re questioning and why.
No, not really. And I disagree with the premise, "They must be a target for the various hacking groups out there."
How would you even hack them? I'm a developer too; how would you hack me?
Options range from carefully targeted phishing or social engineering attacks to poor opsec and a five dollar wrench.
> a five dollar wrench.
I'm not even going to respond to this ridiculousness.
I still don't know why anyone thinks that, among all developers in the world, a little indie Mac developer is getting targeted specifically.
> I'm not even going to respond to this ridiculousness.
Why is it ridiculous? If you have electronic access to something of value and broadcast that fact on the internet, you’re at risk of a physical attack. That’s not controversial? Companies make employees do training about this for a reason.
> If you have electronic access to something of value and broadcast that fact on the internet, you’re at risk of a physical attack. That’s not controversial? Companies make employees do training about this for a reason.
You're talking as if all all "value" and all "risk" is equal, when they're definitely not. You can't equate a megacorporation with a little indie developer. Nobody cares about the latter.
I am a software developer, and I broadcast that fact on the internet. But nobody is coming to Wisconsin to hit me on the head with a wrench. That's just a silly paranoid fantasy.
If anyone hits me on the head with a wrench, it would be not be a nation-state but rather a two-bit local mugger who has no idea who I am and just wants cash from my wallet. I live in a pretty safe area though.
Nobody that you know of.
Some targets are more valuable than others. A firewall product has obvious security value. The fact that it requires high privilege is another reason.
I have the same thoughts about other Mac apps. e.g. iTerm2 - cause they "see" so much sensitive data.
[flagged]
Yeah just yolo install whatever, it’s not like applications or libraries such as axios which have a decade of trusted history would all of a sudden become malicious and do nasty things to developer machines, just chill, everything’s fine.
> Yeah just yolo install whatever
That's not even remotely what I said.
> it’s not like applications or libraries such as axios
iTerm doesn't use NPM. Little Snitch doesn't use NPM. I don't use NPM.
[flagged]
WTF? This is not an acceptable comment on HN, no matter who or what you're replying to. This style of commenting is not what this site is for, and destroys what it is for.
If you wouldn't mind reviewing https://news.ycombinator.com/newsguidelines.html and taking the intended spirit of the site more to heart, we'd be grateful.
The same people who targeted the open source uncommercial library axios *last week*?
Access to little snitch would be worth millions to the right party.
>> I still don't know why anyone thinks that, among all developers in the world, a little indie Mac developer is getting targeted specifically.
> The same people who targeted the open source uncommercial library axios last week?
axios is an NPM package. Little Snitch doesn't use NPM. Thus, these people must be pretty damn incompetent if they were trying to target Little Snitch.
> Access to little snitch would be worth millions to the right party.
This is a bold claim with no evidence. I don't think it's true.
Shell (and probably root) access to tens of thousands of development machines wouldn’t be worth millions to the right party?
?! The same way every other developer that has been hacked. You surely cannot be suggesting you're un-hackable. That seems ludicrously hubristic.
> The same way every other developer that has been hacked.
There's not one single way, so, no, you're just hand-waving here.
Just saying developers have been hacked. Underrated existence proof.
> Just saying developers have been hacked.
So are you going to have this same discussion in every HN submission that mentions any piece of software?
What software do you actually develop? You clearly don’t give a shit about your users and I want to make sure I’m not using your software .
Finally!
Honestly I think it is odd such a tool isnøt considered as standard to an OS as a process manager.
Anyway, this one looks great. I hope Linux distros will incorporate this or similar into the network widgets.
Of course, getting data uploads past little snitch is an exercise in triviality. For instance, using DNS tunneling. Sending requests to unrelated servers, ideally on AWS or some other cloud, so you have no idea at all who's behind the server and the firewall can't realistically block it, where the info can be retrieved by another party.
Neat! Too bad it's proprietary closed-source though (at least the daemon is).
Is there a way to kill little snitch completely without screwing up my DNS/other things?
Which one? Mac or Linux? For the Linux Snitch, just stop the service. For the macOS Snitch, you need to move the app to the trash via Finder. Only Apple can remove the network extension and they do this only when deleted via Finder.
i will never understand why people will flock to this but opensnitch which is just better, fully open and has existed for longer (on linux) gets ignored.
Little Snitch is not there to replace OpenSnitch. It's just an additional option you can choose from. Some people might prefer it, others not.
then it pretty obviously is not better?
so a firewall for linux then?
Dope.
Can someone elaborate on the limitations bit?
"Little Snitch for Linux is built for privacy, not security, and that distinction matters. The macOS version can make stronger guarantees because it can have more complexity. On Linux, the foundation is eBPF, which is powerful but bounded: it has strict limits on storage size and program complexity. Under heavy traffic, cache tables can overflow, which makes it impossible to reliably tie every network packet to a process or a DNS name. And reconstructing which hostname was originally looked up for a given IP address requires heuristics rather than certainty. The macOS version uses deep packet inspection to do this more reliably. That's not an option here."
Is this a limitation of the eBPF implementation? Pardon my ignorance, I'm genuinely curious about this.
eBPF limits the size of the code, its complexity and how data can be stored. You cannot just implement any algorithm in eBPF for that reason.
That's not only a weakness, it's also a strength of eBPF. This way it can provide security and safety guarantees on the code loaded into the kernel.
Yess, the return of the actually good landing page for the technically-minded. Now all they need to do is roll back the macOS one that looks and reads like it was designed by a marketing agency that knows nothing about computers (or even Little Snitch itself).
Now I can spy on the software spying at me. Nice.
The ultimate turnaround would be if the little snitch is snitching on the user too.
It’s not really necessary on Linux. Linux systems work without 40 invisible background services phoning home to the mothership to leak your hardware identifiers for FAA702 collection.
Linux maybe, not so true of all the DEs and apps installed on it
Why would one use this over PiHole?
This is different. This shows you what in your operating system is making connections out and to where.
I run both (LS on Mac, at least), they do different things - pi.hole is a great ad blocker which applies to all of the devices on your network. Little Snitch is doing something different - it tells you every call that every app you use is making, and allows you to approve or deny each one. So, you can block telemetry for apps, or you can block certain apps from contacting certain servers, or you can just use it to watch what apps on your system are calling out to where.
To clarify, I'm aware that pihole is not intended to run on a client OS, and doesn't monitor at a process level. I'm focused on the intended effect rather than the process itself (blocking malicious/ad servers). And I think I framed my initial question incorrectly as if LS and PiHole as subtitutes. It's perfectly fine and even preferrable to use both as layered protection. I'm just thinking however when it comes for bang-for-buck it seems like PiHole is the better value proposition if you could only set up one.
pi.hole is primarily billed as an ad blocker, but the fundamental way it works is by applying a curated set of DNS lists that are blocked (commonly telemetry and ad servers), and the admin dashboard which is just a web page (therefore works on all platforms, smartphones included) will do the same thing: it tells you every call that every app on every device on your network is making, and you can approve or deny it. You can curate your own list as well and block servers/connections you don't want on the network.
LS afaik operates in the same area where it's intended to be used for privacy. I guess I could see it being useful for people who don't have admin access to their router, but for people who do have such access I would think the benefits of network-wide DNS monitoring/blocking would outweight the costs of having to configure your router settings.
Yeah, if you're just looking for ad blocking, you're right, pi.hole is the better bet.
Little Snitch is intended for per-process, per-connection blocking - for example, you may need, eg, an Instagram uploader app to contact Meta's servers, but an unrelated app should not be able to (and even in the case of the hypothetical IG uploader, you can get very fine grained about the controls - media.facebook.net, not telemetry.facebook.net). In that way, LS does have some advantages over pi.hole in that space - You'd need to set up every single item that you normally get for free from a blocklist, but it gives you much finer control over what's getting blocked and much better visibility into what connections your processes are trying to make.
Again, I don't think Little Snitch is the right answer if you're looking for ad blocking specifically, and if that's the extent of your privacy concerns, pi.hole's a better bet. Little Snitch is a per-application connection monitor and firewall - it _can_ block ads, but that's not its primary purpose.
LS seems to not be claiming any security promise on Linux because it can't make any guarantees given eBPF limitations. But the entire purpose is different and there is very little overlap in my view. PiHole is entirely (I think?) just applying the blocklist made easy. LS allows you to build the blocklist in real time.
I would guess that to the extent the blocklists include things that are loaded by applications and not websites, they are almost entirely built by users of something like LittleSnitch or OpenSnitch. This is also entirely doable with wireshark logs, but I think that requires more infrastructure to build into usable lists.
Some telemetry uses hardcoded addresses when DNS doesn't work.
Some telemetry might not be recognized by pi-hole as it is new or has nothing to do with ads.
LittleSnitch isn't for ad blocking (only), it is for tracking/blocking/allowing ALL connections from various processes. PiHole only blocks DNS requests to known ad servers.
Completely different thing. A littlesnitch type thing is for all traffic. Pihole is a DNS query thing that prevents various ad content from being loaded. It's also trivially easy for a malicious application with network access to bypass any instance of pihole on your LAN by doing its own DNS over HTTPS lookups to its own set of server(s) by IP.
I mean, if you're at the point where your machine is compromised by a process with full network access little snitch won't help much either.
You might be surprised, there are plenty of low effort attacks out there that just install a crypto miner and phone home periodically without doing much to cover it up.
good
Really like Lulu as an alternative to LittleSnitch https://objective-see.org/products/lulu.html
Have you ever checked Calico or Cilium, or at least, Oryx?
eBPF programs are able to accuratly process network traffic in high performance, but the amount of CPU instructions you can use is limited. Otherwise it would not be high performance. This limits the complexity of in-kernel processing.
Thank you for the response. Yet, how the heck the CPU instructions you inject in (that are being processed within the same network processing) limit the capabilities of the flow, if you literally put your calls within the same networking context? Please provide any actual document that proves your point.
I guess you haven't actually implemented anything in eBPF.
I have, but in the scopes of Kprobes non-network but memory. Here, I am sure you haven't at this point. I also provided projects you may check prior stating another nonsense. Instead, you could also provide some more evidence you disagree with.
Can you elaborate? I thought eBPF was created to be used in high performance scenarios, so I am confused why this shouldn't be posssible.
Great website features, exactly what I needed, thank you.