At $work we use Tailscale mostly because we were running into too many random issues with NAT with our standard DIY Wireguard setup, especially when people were working from hotels and other places with half-ass network setups.
But we don't trust Tailscale. Just look at the thousands of unresolved Github issues, many of which are actually quite important/useful but have been ignored for months and years.
We very much fear at $work that there are vulnerabilities in the Tailscale product awaiting discovery. Especially as, AFAIK, Tailscale have never had a formal security audit on their software.
So we install it on hardened bastion hosts in an old-school "jump host" model. So people can still get access to where they need to be, but we don't need to install Tailscale's unaudited shit on every single server / vm / etc.
And we only use Tailscale as a glorified VPN, we don't use their hundreds of extra random features like this SSH one.
In terms of SSH, we use old-school OpenSSH and SSH certificates. Its really not that difficult and its really not expensive, you can do offline signing with Yubikeys, no need for expensive HSMs.
> And we only use Tailscale as a glorified VPN, we don't use their hundreds of extra random features like this SSH one.
Same, you are not alone.
The Tailscale VPN stuff just works. None of their competitors can claim this that I'm aware of. We tried several other products and none of them were as reliable and 'just worked'. I imagine they spend a lot of time just keeping that stuff working.
> Spoiler alert: This applies to all software. This is why security preaches defense in depth.
Thank you Mr/Mrs Pedant.
However this is a VPN product I am talking about which has an integral part in the defence in depth of which you speak.
Therefore it is only right and proper that I, and others, should be able to trust them to a greater degree. Never 100% of course, as you say. But if you are selling me a security product then you should be able to demonstrate you have put some damn effort into securing it.
"insecure argument handling" in a security product is not a good look. It stinks of sloppy coding practices followed up by a lack of security auditing.
I've been planning a similarly "paranoid" (but apparently not that paranoid) Tailscale setup, for the same reasons.
Another concern I have is whether a compromise of Tailscale's own infra could let an attacker just add itself to my network. Apparently the "Tailnet Lock" feature mitigates this, but it is off by default. If I was an APT, compromising Tailscale would be priority number 1!
> Another concern I have is whether a compromise of Tailscale's own infra could let an attacker just add itself to my network. Apparently the "Tailnet Lock" feature mitigates this, but it is off by default.
Yeah, we use "tailnet lock" to sort of cover that. AFAIK its the only option available.
I say "sort of" because "tailnet lock" is a bit half-assed in its design and implementation.
For example, you cannot sign new nodes from mobile devices (e.g. iOS). And as we know, locking down iOS is easier than a full desktop machine. So that's a bit of a missed opportunity. And as usual, there's a Tailscale Github issue open for it for years ...
And in practice, the "tailnet lock" addition is done through the `tailscale` software on the desktop/laptop. Its click a button or run a CLI without further authentication/authorisation required. So basically anyone could do it. And the keys are, of course, open to exfiltration, you can't use a Yubikey or anything like that. And you can't require multi-signer. Complete joke really.
Also if you use "tailnet lock" with the Tailscale Mullvad integration, its a one-way street. You can sign Mullvad nodes so they can be used as exit nodes, but it is impossible to revoke signatures from obsolete/replaced Mullvad nodes (with tailscale clients, you simply delete them from the org which means they have to re-auth and re-join under a new ID ... but you can't do that with the Mullvad integration, so the 'ghost' exit node could easily return). Your only option is to remove the signing node that signed the Mullvad nodes and start again from scratch. Another joke.
So, yeah, "better than nothing" is the way I would summarise "tailscale lock".
Genuine question, if you use bastion hosts, why do you need Tailscale? Why not to expose tcp/22 to the internet and allow public key authentication only (or, certificate based one, if you prefer fancy)? OpenSSH security track record seems to be better than that of Tailscale.
> Genuine question, if you use bastion hosts, why do you need Tailscale? Why not to expose tcp/22
Fair question. The short answer is my wording was a little off.
We do have pure SSH bastion hosts. Those are OpenBSD-based with a few tweaks, but basically they are locked-down and heavily monitored to within an inch of their life.
The reason Tailscale is there is mostly so the non-techies can access intranet portals and such-like.
But Tailscale does have a useful party-trick for the techies too, in that you can do DNS-suffix based routing (without needing to use Tailscale's DNS).
So they can automagically hop via a Tailscale bastion host to "*.$region.rds.amazonaws.com" or whatever. You just specify the DNS suffix and anything on that wildcard will work. It therefore enables us to further harden access to that stuff to a source IP of the Tailscale bastion hosts (in addition to the usual security stuff, of course).
Tailscale takes care of the automagic load-balancing/re-routing to the Tailscale bastion hosts, so we just have a bunch installed in random geographically-dispersed places and as long as >0 are up and running the Techies will always have a route to where they need to be.
Obviously the above is over-simplified summary before the pedants start picking it apart. ;)
Am aware of them but IIRC they are both unaudited which kind of brings us back to square one ? We would still end up running them at arms-length as we do with Tailscale at the moment.
Isn't Headscale server-side only ?
Also a bit strange that "Tailscale vs Netbird" doesn't feature more prominently on their "Compare Netbird" page. It is hidden behind "Load More". ;D
> Tailscale contracts with cybersecurity firm Latacora to conduct
And these published audits of the `tailscale` software are where ?
Even half-serious VPN providers like Mullvad publish in public their regular security audits of their app and infrastructure.
There is zero reason Tailscale cannot do the same.
And frankly, given the nature of this vulnerability, "insecure argument handling" I'm not entirely sure it has been audited ? Or if it has, they should be looking for a new auditor ASAP !
> I'd class Mullvad as the most serious VPN provider
I agree. Its annoying that lots of places have recently been blanket-banning Mullvad IP ranges.
Their sister-company Tilitis[1] is also doing interesting things with the Tkey product.
The present version has limitations due to the original security model but the up-and-coming version has a revised security model to make things a bit more "real-world" useful whilst not making any security trade-offs.
> we don't trust Tailscale. Just look at the thousands of unresolved Github issues, many of which are actually quite important/useful but have been ignored for months and years.
This is a poor measure of quality. I've spent considerable time knee-deep in these issues in particular and the vast, vast majority of them are feature requests, bug reports awaiting more information from the submitter, or bug reports that cannot easily be reproduced (likely conflicts with other software). On the whole, Tailscale does an excellent job of "just working" in practically every possible environment. They do an incredible job thriving in the diverse ecosystem of software networking and their work will naturally never be remotely done. There will always be gaps, it's the nature of the beast. I'm not aware of any other product that does a better job here.
If you've spent any time dealing with enterprise software you'd know that there is an infinite firehose of these sort of issues. We're lucky that Tailscale keeps these public. Many other vendors track these sort of issues privately.
If there are particular issues which jeopardize the security posture of Tailscale deployments that have been open for a significant amount of time, my clients and I would love to know. Please share!
> We very much fear at $work that there are vulnerabilities in the Tailscale product awaiting discovery. Especially as, AFAIK, Tailscale have never had a formal security audit on their software.
I can't take this seriously. If you were a customer you could, you know, ask them? Or inspect their SOC2 documents?
I absolutely guarantee they undergo regular formal security audits. There's no question.
> So we install it on hardened bastion hosts in an old-school "jump host" model. So people can still get access to where they need to be, but we don't need to install Tailscale's unaudited shit on every single server / vm / etc.
Bastion hosts are a terrible model in 2026. I can't take this approach seriously.
> we don't need to install Tailscale's unaudited shit on every single server / vm / etc.
You never need to do this. Simply create an exit node into your subnet, and everything you want becomes routable.
It sounds to me like your architecture struggles with a zero-trust network approach if you view this as a blocker. I've got some slots available if you need a consultation!
> In terms of SSH, we use old-school OpenSSH and SSH certificates. Its really not that difficult and its really not expensive, you can do offline signing with Yubikeys, no need for expensive HSMs.
It's expensive in terms of engineer-hours, especially compared to Tailscale. It's also easy to get wrong, and end up with the same vulnerability as TFA, or worse.
But my main issue is that if you see this as equivalent it's telling me that you're not really the target audience. Your set-up is far more vulnerable than the out-of-the-box experience you get with Tailscale. If you don't mind, then I'm happy for you.
Lastly, I don't work for Tailscale and I'm not affiliated with them in any way beyond being a happy user that has solved a lot of problems very easily with their product. I highly recommend it to practically everyone. It's great.
I'm having a hard time taking your comment seriously. It just seems like non-constructive FUD.
> I absolutely guarantee they undergo regular formal security audits. There's no question.
Well, they clearly don't if they have an "insecure argument handling" vulnerability.
As others here have said already here, its an "venerable and ancient class of bugs".
Its the sort of thing that should be picked up by modern defensive programming that includes fuzz testing.
And it is CERTAINLY the sort of thing that should be flagged by any competent security audit. "insecure argument handling" is bread-and-butter for security auditors.
> I can't take this seriously. If you were a customer you could, you know, ask them? Or inspect their SOC2 documents?
SOC2, ISO27001 and all that shit is not the same thing.
As I said, anyone serious who is proud of having had their software audited as clean would publish their reports in public. Nothing to hide. And it strengthens your case with customers.
It can always be a suitably redacted management summary written by the auditor. That's what everyone else does.
I'm somewhat alarmed that the context that this bug was running in was capable of root login. Is there a reason that an SSH login process would, by default, have enough capabilities to facilitate direct root login?
Making a useful multi-uid-capable daemon that can’t become root but is not so nerfed that no one uses it is nontrivial. If nothing else, what policy would you use? Why do you think that no other uid is equivalent to root?
If it runs as your user and can only log in as you, then I wouldn't expect it to be able to become root. But if it can log you in as different users, I would expect that 1. it needs to run from root, and 2. it can log in as root.
We did Tailscale-like SSH reverse tunnels at scale first in 2013 and the main issue has always been that there are no good libraries. Bash scripting around the OpenSSH binaries is pretty much the only way to go.
There's Paramiko, but Python is still a huge liability in memory-constrained systems.
libssh, libssh2. These are totally independent and unrelated code bases, libssh is maintained by Red Hat mainly for ansible and some other tools, libssh2 was created for curl. libssh2 is client-only, libssh can also be used to implement servers.
I’m a heavy Tailscale user, so I do trust them quite a bit, but I never used the Tailscale SSH feature.
I feel like OpenSSH’s security record is pretty unbeatable, not sure why I’d swap over for such a security-sensitive tool.
The SSH vulnerability here only applies if the attacker is already on the network. It violates your Tailscale ACLs, but it's not arbitrary external root ssh access. Arguably that's a more secure starting point than vanilla ssh to publicly accessible machine.
OTOH, if you run vanilla ssh on a publicly accessible machine where only port 22 is open, sshd only allows publickey-based authentication and the only accepted key types are FIDO2/U2F hardware-backed keys, it's probably more secure again (less attack surface).
Unless you're using short lived SSH CA certificates, SSH key access has only modest security. You would need to buttress it with TOTP 2FA or enforce Yubikey generation/storage of keys, neither of which are at all default.
Even then, it's obvious you are running SSH, and they can fingerprint the OS, and external logging shows which machines are connecting, and hence have said SSH keys. If they have SSH open they become targets; if they come from CGNAT, carriers can leak location via CGNAT behaviour.
With a plain VPN like WireGuard when they get access to your network, they don't have plain ssh, not to mention root ssh access to hosts. This is a serious issue.
I just don't use stranger's machines to access my personal stuff. Possibly compromised stranger's machines.
I don't see the benefit about that, as I have more laptops than I need.
I used it for a bunch of remote monitor boxes to have a way of centrally managing ssh access to things that were often on- and off-line. It was simple and convenient and access was easily revocable.
The proper fix would be to not use getent CLI tool in their logic, but instead use proper system APIs for looking up user account entries, like one of earlier comments here already mentions. This is shocking amateur hour!
My guess is they hastily threw together something hacky in early development, and forgot to replace it with a real, safe solution later.
The issue here is there is NO single system API for looking up user account entries on Linux.
It's implemented in libc. So you need to link to libc. Tailscale is a Go binary, and they probably prefer it to be statically-linked. glibc NSS implementation also REQUIRES you to load `.so` so you just can't emulate it in Go.
But of course there is, it's part of POSIX, implemented in libc. And if you're using a higher level language, they all have their own wrappers around libc/POSIX APIs. Here is golang's: https://pkg.go.dev/os/user
Others have pointed out that os/user.Lookup is a platform-independent way to resolve this, but additionally you don’t _need_ to link against glibc to use it.
If you are writing go, you usually want to set CGO_ENABLED=0 by default, to avoid inadvertently introducing nonportable code. In this way, only the pure Go implementations are used and there is no need to link (statically or dynamically) against a libc implementation to compile and run your programs.
There is a whole class of security issues where fixes are worse that the issues themselves. Case in point, the OpenSSH itself that sends 100 packets on each keystroke to avoid timing attacks.
Why is that worse than the issue itself? If someone could figure out, say, my root password via an ssh timing attack, that seems bad. Sending 100 packets for each keystroke to protect against this seems cheap in the face of that.
I don't see the point of publishing a security bulletin if you are not going to timely push the fix to artifacts on all affected platforms. Tailscale needs to do better on their release process, docker hub shows last update was 8 days ago.
I don't mind having a bulletin so much as the claim that it's fixed in 1.98.9 or newer, when that release doesn't appear to exist yet. Feels pretty weird practice to advise upgrading to a non-existent version.
1.98.9 has already been tagged since bulletin was published (don't know why they chose on github to tag but not release).
1.98.9 version exists! That's not the question. It should already have been made available for Linux distros assuming this resource from Tailscale is accurate https://pkgs.tailscale.com/stable/?v=1.98.9
I also run self-hosted Wireguard. Initially on a Debian box, nowadays it is integrated into my router (admittedly, this is closed source). For around 6 years at this point.
The whole thing could not be easier and simpler. It has never randomly broken on me. It is fast. It is free. There is no middle man, no vendor.
I never understood the popularity of Tailscale, though that is on me. I'm sure it is a great product, I just never tried it, do not seem the target audience.
What confuses me is the often accompanying, sometimes aggressive anti-selfhosting stance in these sorts of threads. I do not see this in other topics, e.g. someone mentioning they run Jellyfin isn't met with "why not Plex?". Where does that come from? We are on HackerNews, not ProductShillNews, aren't we? I guess self hosting Wireguard is too boring to warrant any further discussion? The VPN equivalent of a Toyota Corolla.
My WireGuard uses (either at home or at work) are very much mobile client to single network
Where Tailscale comes into its own is automatic managing of mesh networking (like an “sdwan” solution). The other thing it excels at is firewall busting - if you have a firewall (with or without address translation) which only allows outgoing traffic to be established (with UDP timeouts for session) then Tailscale also works in a similar way to turn/stun.
If I needed that capability then I’d be looking at Headscale. I don’t need it though.
Remember that this is hackernews, not slashdot. Where the community used to be far smaller and the technology far smaller it was quite normal for everyone to understand basic building blocks of ip addresses, use open source software, wear t-shirts threatening to replace people with a small shell script etc.
It’s not the same community, many people here have no real understanding of computer fundamentals, but instead have expertise in specific narrow areas. They also have little interest in things like free software, but do have an interest in building a new billion dollar company to sell to a behemoth.
Some would consider that an anti-feature. Firewalls are not to be busted. Nothing good lies at the extreme end of working around overly strict policies. Change the policy instead.
I think Tailscale is popular because of how plug and play it is for most people. Although the main reason I use it over self hosting wireguard is the NAT busting it does, which has so far worked flawlessly for me with no setup aside from installing on both devices. There is nothing wrong with self hosting wireguard, but it doesn't actually do the same job as tailscale.
Wireguard by itself also doesn't allow for 2FA or expiring keys. Not as relevant for private use, but some orgs need it for compliance. The idea was always that things like that need to be implemented by an application on top of it, so you end up with something like tailscale eventually.
i have my homelab only reachable via tailscale and can access everything i would ever want on the go that way. it was a matter of 15 min to get it all working.
> I never understood the popularity of Tailscale, though that is on me.
> I guess self hosting Wireguard is too boring to warrant any further discussion?
It's popular because you don't have to deal with NAT punching. It "just works", all the time. And Wireguard is not too boring, it's just not enough on its own.
I'm all for self-hosting and this is exactly why I prefer to use Tailscale and not have to manage jump-hosts and STUN points on some cloud, given that I won't be able to make it as reliable as Tailscale and as cheap as Tailscale (effectively $0). So this is literally the only tradeoff I made while self-hosting everything else.
it wasn't meant as a rebuttal, I'm genuinely asking. tailscale + headscale was just recommended to me, hence that's what I'm using for self hosting. is wireguard's client roughly equivalent to tailscale's? especially tailscale's always-on nature is very appealing.
I found Netbird to be easier to implement. Among its peers it seems to be the most complete open source solution. It IS a bit fast moving though so there might be issues. And they just added an Agent network thing that nobody asked for but it's par for the course these days.
Because wireguard to tailscale is like git to git GUIs. It's solid base but never should be used separately without a proper wrapper if one wants to keep one's sanity.
If you don't care to invest half an hour into learning some basics of how computer networking and in particular CIDR notation and subnet masks work, maybe it is not for you.
Not necessarily, it's a clean room implementation. Even if leading dashes was known/documented/tested to implement they might have done it differently. And maybe it was an implementation detail that it was ever allowed, but that's a weird username, headscale implementation happened not to allow it, and nobody ever noticed the discrepancy.
I presume Ada Logics has access to Anthropic's Mythos model via Project Glasswing, and Ada Logics discovered this exploit during their vulnerability research.
It takes over port 22 on the Tailscale interface only. Only had problems with this when I’ve wanted to hit a host’s non-Tailscale ssh service via Tailscale. Otherwise it’s been great for me
If it used one of the standard system APIs for looking up user accounts (e.g. getpwnam(3)), there's no way it can happen.
This is incredibly bad engineering, on level of a SQL injection, in 21st century. Something a highschool student experimenting with scripting could come up with, but not a supposedly professional software company.
It lets organizations (Tailscale) control the timing and narrative around the disclosure more directly. Organizations sometimes avoid the bureaucracy of going through CVE Numbering Authorities by self-publishing. Often a CVE assignment follows self-disclosure, especially when there's pressure to interoperate with vuln-scanning/compliance tooling
A better fix is to call “getent passwd” with no user controlled arguments and then parse the resulting list. This gets rid of the input sanitization problem entirely.
A correct implementation would be to just call glibc directly, this seems like a hasty fix to get the patch out the door. The history of vulns from bad shell escaping is as old as bash, whenever possible you probably shouldn't be mixing code and data, especially in a security critical application like this.
The fact that there is no portable way to link the relevant functions that works reliably across all distributions of Linux is a failure of POSIX and GNU, and unfortunately is largely the Linux distribution story in a nutshell.
Your answer is mostly correct, except that when you tug on that thread the shelf comes off the wall, the plaster comes with it, and then it cracks the water pipes on the way to the floor.
I argue the opposite: there’s no better fix for this. You can write the most elegant fix, whatever it is, and prevent that from happening only on the codebase that’s fixed. That doesn’t mean that the codebase will always be the only authority on authentication.
The username policy fixes this issue for good, regardless of whatever you write in the future, or whatever new mechanism is introduced.
It’s a restriction for sure, but it’s not a nonsense restriction? Who would have a username starting with a hyphen? I didn’t even know it was possible until today.
But we don't trust Tailscale. Just look at the thousands of unresolved Github issues, many of which are actually quite important/useful but have been ignored for months and years.
We very much fear at $work that there are vulnerabilities in the Tailscale product awaiting discovery. Especially as, AFAIK, Tailscale have never had a formal security audit on their software.
So we install it on hardened bastion hosts in an old-school "jump host" model. So people can still get access to where they need to be, but we don't need to install Tailscale's unaudited shit on every single server / vm / etc.
And we only use Tailscale as a glorified VPN, we don't use their hundreds of extra random features like this SSH one.
In terms of SSH, we use old-school OpenSSH and SSH certificates. Its really not that difficult and its really not expensive, you can do offline signing with Yubikeys, no need for expensive HSMs.
Same, you are not alone. The Tailscale VPN stuff just works. None of their competitors can claim this that I'm aware of. We tried several other products and none of them were as reliable and 'just worked'. I imagine they spend a lot of time just keeping that stuff working.
Spoiler alert: This applies to all software. This is why security preaches defense in depth.
Thank you Mr/Mrs Pedant.
However this is a VPN product I am talking about which has an integral part in the defence in depth of which you speak.
Therefore it is only right and proper that I, and others, should be able to trust them to a greater degree. Never 100% of course, as you say. But if you are selling me a security product then you should be able to demonstrate you have put some damn effort into securing it.
"insecure argument handling" in a security product is not a good look. It stinks of sloppy coding practices followed up by a lack of security auditing.
Another concern I have is whether a compromise of Tailscale's own infra could let an attacker just add itself to my network. Apparently the "Tailnet Lock" feature mitigates this, but it is off by default. If I was an APT, compromising Tailscale would be priority number 1!
Yeah, we use "tailnet lock" to sort of cover that. AFAIK its the only option available.
I say "sort of" because "tailnet lock" is a bit half-assed in its design and implementation.
For example, you cannot sign new nodes from mobile devices (e.g. iOS). And as we know, locking down iOS is easier than a full desktop machine. So that's a bit of a missed opportunity. And as usual, there's a Tailscale Github issue open for it for years ...
And in practice, the "tailnet lock" addition is done through the `tailscale` software on the desktop/laptop. Its click a button or run a CLI without further authentication/authorisation required. So basically anyone could do it. And the keys are, of course, open to exfiltration, you can't use a Yubikey or anything like that. And you can't require multi-signer. Complete joke really.
Also if you use "tailnet lock" with the Tailscale Mullvad integration, its a one-way street. You can sign Mullvad nodes so they can be used as exit nodes, but it is impossible to revoke signatures from obsolete/replaced Mullvad nodes (with tailscale clients, you simply delete them from the org which means they have to re-auth and re-join under a new ID ... but you can't do that with the Mullvad integration, so the 'ghost' exit node could easily return). Your only option is to remove the signing node that signed the Mullvad nodes and start again from scratch. Another joke.
So, yeah, "better than nothing" is the way I would summarise "tailscale lock".
Fair question. The short answer is my wording was a little off.
We do have pure SSH bastion hosts. Those are OpenBSD-based with a few tweaks, but basically they are locked-down and heavily monitored to within an inch of their life.
The reason Tailscale is there is mostly so the non-techies can access intranet portals and such-like.
But Tailscale does have a useful party-trick for the techies too, in that you can do DNS-suffix based routing (without needing to use Tailscale's DNS).
So they can automagically hop via a Tailscale bastion host to "*.$region.rds.amazonaws.com" or whatever. You just specify the DNS suffix and anything on that wildcard will work. It therefore enables us to further harden access to that stuff to a source IP of the Tailscale bastion hosts (in addition to the usual security stuff, of course).
Tailscale takes care of the automagic load-balancing/re-routing to the Tailscale bastion hosts, so we just have a bunch installed in random geographically-dispersed places and as long as >0 are up and running the Techies will always have a route to where they need to be.
Obviously the above is over-simplified summary before the pedants start picking it apart. ;)
Am aware of them but IIRC they are both unaudited which kind of brings us back to square one ? We would still end up running them at arms-length as we do with Tailscale at the moment.
Isn't Headscale server-side only ?
Also a bit strange that "Tailscale vs Netbird" doesn't feature more prominently on their "Compare Netbird" page. It is hidden behind "Load More". ;D
https://tailscale.com/security
And these published audits of the `tailscale` software are where ?
Even half-serious VPN providers like Mullvad publish in public their regular security audits of their app and infrastructure.
There is zero reason Tailscale cannot do the same.
And frankly, given the nature of this vulnerability, "insecure argument handling" I'm not entirely sure it has been audited ? Or if it has, they should be looking for a new auditor ASAP !
I agree. Its annoying that lots of places have recently been blanket-banning Mullvad IP ranges.
Their sister-company Tilitis[1] is also doing interesting things with the Tkey product.
The present version has limitations due to the original security model but the up-and-coming version has a revised security model to make things a bit more "real-world" useful whilst not making any security trade-offs.
[1] https://www.tillitis.se/
This is a poor measure of quality. I've spent considerable time knee-deep in these issues in particular and the vast, vast majority of them are feature requests, bug reports awaiting more information from the submitter, or bug reports that cannot easily be reproduced (likely conflicts with other software). On the whole, Tailscale does an excellent job of "just working" in practically every possible environment. They do an incredible job thriving in the diverse ecosystem of software networking and their work will naturally never be remotely done. There will always be gaps, it's the nature of the beast. I'm not aware of any other product that does a better job here.
If you've spent any time dealing with enterprise software you'd know that there is an infinite firehose of these sort of issues. We're lucky that Tailscale keeps these public. Many other vendors track these sort of issues privately.
If there are particular issues which jeopardize the security posture of Tailscale deployments that have been open for a significant amount of time, my clients and I would love to know. Please share!
> We very much fear at $work that there are vulnerabilities in the Tailscale product awaiting discovery. Especially as, AFAIK, Tailscale have never had a formal security audit on their software.
I can't take this seriously. If you were a customer you could, you know, ask them? Or inspect their SOC2 documents?
I absolutely guarantee they undergo regular formal security audits. There's no question.
> So we install it on hardened bastion hosts in an old-school "jump host" model. So people can still get access to where they need to be, but we don't need to install Tailscale's unaudited shit on every single server / vm / etc.
Bastion hosts are a terrible model in 2026. I can't take this approach seriously.
> we don't need to install Tailscale's unaudited shit on every single server / vm / etc.
You never need to do this. Simply create an exit node into your subnet, and everything you want becomes routable.
It sounds to me like your architecture struggles with a zero-trust network approach if you view this as a blocker. I've got some slots available if you need a consultation!
> In terms of SSH, we use old-school OpenSSH and SSH certificates. Its really not that difficult and its really not expensive, you can do offline signing with Yubikeys, no need for expensive HSMs.
It's expensive in terms of engineer-hours, especially compared to Tailscale. It's also easy to get wrong, and end up with the same vulnerability as TFA, or worse.
But my main issue is that if you see this as equivalent it's telling me that you're not really the target audience. Your set-up is far more vulnerable than the out-of-the-box experience you get with Tailscale. If you don't mind, then I'm happy for you.
Lastly, I don't work for Tailscale and I'm not affiliated with them in any way beyond being a happy user that has solved a lot of problems very easily with their product. I highly recommend it to practically everyone. It's great.
I'm having a hard time taking your comment seriously. It just seems like non-constructive FUD.
Well, they clearly don't if they have an "insecure argument handling" vulnerability.
As others here have said already here, its an "venerable and ancient class of bugs".
Its the sort of thing that should be picked up by modern defensive programming that includes fuzz testing.
And it is CERTAINLY the sort of thing that should be flagged by any competent security audit. "insecure argument handling" is bread-and-butter for security auditors.
> I can't take this seriously. If you were a customer you could, you know, ask them? Or inspect their SOC2 documents?
SOC2, ISO27001 and all that shit is not the same thing.
As I said, anyone serious who is proud of having had their software audited as clean would publish their reports in public. Nothing to hide. And it strengthens your case with customers.
It can always be a suitably redacted management summary written by the auditor. That's what everyone else does.
The finding in TFA was the result of a security audit.
Don't you fucking dare.
Might I point you to the words "We would like to thank Anthropic and Ada Logics for reporting this issue.".
It was not commissioned by Tailscale. It was DONE BY OTHERS AND REPORTED TO TAILSCALE. Just like the fucking disclosure tells you.
Tailscale should not be relying on the random goodwill of others to do random audits of unknown coverage at random intervals.
That is not a serious approach to security.
They should be commissioning their own, paid out of their own pocket, at regular intervals, and publishing the results.
(If you had SSH access to a host in your Tailscale ACL, you could log in as `-i` and get a root login.)
There's Paramiko, but Python is still a huge liability in memory-constrained systems.
Even then, it's obvious you are running SSH, and they can fingerprint the OS, and external logging shows which machines are connecting, and hence have said SSH keys. If they have SSH open they become targets; if they come from CGNAT, carriers can leak location via CGNAT behaviour.
In contrast tailscale makes this much harder.
Always try to use actual API/system calls (in this case getpwnam) instead of calling sub-processes.
Is the proper fix not restricting users not possible in these poorly designed ancient systems?
Similarly re another issue: why not just fix the permission issues instead of restricting users?
> Tailscale now disallows the use of UIDs or numeric-only usernames via SSH to avoid this ambiguity
My guess is they hastily threw together something hacky in early development, and forgot to replace it with a real, safe solution later.
It's implemented in libc. So you need to link to libc. Tailscale is a Go binary, and they probably prefer it to be statically-linked. glibc NSS implementation also REQUIRES you to load `.so` so you just can't emulate it in Go.
Then, "link to libc". Which libc? glibc? musl?
If you are writing go, you usually want to set CGO_ENABLED=0 by default, to avoid inadvertently introducing nonportable code. In this way, only the pure Go implementations are used and there is no need to link (statically or dynamically) against a libc implementation to compile and run your programs.
Yes there is, and you answered in the next line, it is implemented in libc.
If you want to check authentication use libc don't try to implement crypto and authentication yourself.
1.98.9 version exists! That's not the question. It should already have been made available for Linux distros assuming this resource from Tailscale is accurate https://pkgs.tailscale.com/stable/?v=1.98.9
Edit: Their changelog also mentions the version: https://tailscale.com/changelog#all
I also run self-hosted Wireguard. Initially on a Debian box, nowadays it is integrated into my router (admittedly, this is closed source). For around 6 years at this point.
The whole thing could not be easier and simpler. It has never randomly broken on me. It is fast. It is free. There is no middle man, no vendor.
I never understood the popularity of Tailscale, though that is on me. I'm sure it is a great product, I just never tried it, do not seem the target audience.
What confuses me is the often accompanying, sometimes aggressive anti-selfhosting stance in these sorts of threads. I do not see this in other topics, e.g. someone mentioning they run Jellyfin isn't met with "why not Plex?". Where does that come from? We are on HackerNews, not ProductShillNews, aren't we? I guess self hosting Wireguard is too boring to warrant any further discussion? The VPN equivalent of a Toyota Corolla.
Where Tailscale comes into its own is automatic managing of mesh networking (like an “sdwan” solution). The other thing it excels at is firewall busting - if you have a firewall (with or without address translation) which only allows outgoing traffic to be established (with UDP timeouts for session) then Tailscale also works in a similar way to turn/stun.
If I needed that capability then I’d be looking at Headscale. I don’t need it though.
Remember that this is hackernews, not slashdot. Where the community used to be far smaller and the technology far smaller it was quite normal for everyone to understand basic building blocks of ip addresses, use open source software, wear t-shirts threatening to replace people with a small shell script etc.
It’s not the same community, many people here have no real understanding of computer fundamentals, but instead have expertise in specific narrow areas. They also have little interest in things like free software, but do have an interest in building a new billion dollar company to sell to a behemoth.
Some would consider that an anti-feature. Firewalls are not to be busted. Nothing good lies at the extreme end of working around overly strict policies. Change the policy instead.
i have my homelab only reachable via tailscale and can access everything i would ever want on the go that way. it was a matter of 15 min to get it all working.
> I guess self hosting Wireguard is too boring to warrant any further discussion?
It's popular because you don't have to deal with NAT punching. It "just works", all the time. And Wireguard is not too boring, it's just not enough on its own.
I'm all for self-hosting and this is exactly why I prefer to use Tailscale and not have to manage jump-hosts and STUN points on some cloud, given that I won't be able to make it as reliable as Tailscale and as cheap as Tailscale (effectively $0). So this is literally the only tradeoff I made while self-hosting everything else.
Others report no issues but I had massive drain on iOS even with only 4 connections open.
Native wireguard is unnoticeable.
I ditched wireguard for tailscale for the ease of managing it. I'd much rather run my own independently but CBA with the config editing hassle.
Does it do the opposite of that?
it seems anthropic also use tailscale or it's just being discovered by the mythos model?
This is incredibly bad engineering, on level of a SQL injection, in 21st century. Something a highschool student experimenting with scripting could come up with, but not a supposedly professional software company.
As single tailnet+single user, perhaps it's just okay
Really? That's the fix?
A proper fix is to use "--" to separate arguments.
A better fix is to call “getent passwd” with no user controlled arguments and then parse the resulting list. This gets rid of the input sanitization problem entirely.
Your answer is mostly correct, except that when you tug on that thread the shelf comes off the wall, the plaster comes with it, and then it cracks the water pipes on the way to the floor.
Refactoring external invocations to use safe argument handling is a better way to fix it. Along with tests that exercise weird names.
The username policy fixes this issue for good, regardless of whatever you write in the future, or whatever new mechanism is introduced.
It’s a restriction for sure, but it’s not a nonsense restriction? Who would have a username starting with a hyphen? I didn’t even know it was possible until today.
The better fix would be to not have the username pass through a parser looking for cli flags in the first place.
If their scope grows, and they run so much as root, it won't be their last.