Former tailscalar here and now someone managing tailscale at an org.
Having done my own review of the vulns and the fixes as they are landing in github, its pretty clear to me that this only affects situations where you use ACLs to permit ssh into a node (via tailscale ssh, not via opensshd), but dont give a path to sudoers/root.
If a user had no SSH access and/or connectivity to a vulnerable node, none of these vulns give them access.
However, if you have a vulnerable tailscaled and you give ssh access as some non-root account/privs, then yes, these vulns are relevant as theres now known privilege escalations that give access beyond some specific user account.
Not trying to play down the vuln (its important), but its not a free-for-all RCE that some ppl are acting like it is.
Calling it “tailworm” feels like alarmism to promote their find more.
Would only show worm behavior if machines within the tailnet had the right settings and also were members of other tailnets with those settings but then it would require someone in that tailnet to have another tailnet with the right settings…
It’s far fetched.
But a large portion of Tailscale users should be software engineering professionals, so a lot of the time, people use Tailscale just for SSH. I personally feel the impact is still quite big, especially since SSH leads directly to control of the server.
Do you use tailscale ssh but either dont have sudo, or don't permit login as root?
If all your tailscale-ssh ACLs allow you into an account with sudo, or allow you into root, theres no impact (you cant do anything with these vulns you couldnt do a month ago). Thats the nuance I'm trying to get across (admittedly my english is bad).
On the majority of nodes I provide Tailscale SSH access to, it's as root or a user with passwordless sudo. It's being used for admin access. So yeah, on those it doesn't matter as much.
There are a handful which restrict users to their own user accounts. But it's on dev server with friendly devs, so even for that use case it's not really the end of the world.
I'm sure our infosec folks are going to demand that we upgrade everywhere, however.
Engineers use vanilla SSH for SSH, Tailscale SSH is more focused on enterprise stuff where you can have an audit trail of all commands executed and enforce ACLs.
Tailscale SSH is different than doing SSH with Tailscale
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Basically you can use Tailscale for authnz instead of plain old keys and they add some extra logging and stuff [1]
[1] https://tailscale.com/docs/features/tailscale-ssh
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I’ve used tailscale in quite a few jobs now and not one have we used tailscale ssh. Call us old school or whatever but at my current place of employment we provision ssh keys on a box with ansible and just use regular old ssh over the tailnet, not tailscale ssh
I use tailnet as a vpn and ssh into my server via the tailnet, but I dont use tailscale ssh the product. I think most people fall into this bucket.
Of course it should be taken seriously, but this topic is also piggy backing off of 7 days straight of non stop viral engagement farming on X after php2shell, where people we're farming likes by just posting stuff like
"YoU ThInK PhP2ShELl iS BaD JuST WaIt unTiL TaIlScAlE get HaCkED, ThIS JuSt ThE BeGiNNiNG oF a CybeR ReCKoNiNG"
To farm FUD from normies. Which of course led researchers who were working on tailscale vulns to take advantage of that algorithmic attention as well and talk about their research.
Like Im pretty sure we knew about this vuln for 3 days now, or atleast that it was responsibly disclosed (and not being used in the wild).
The attention this is getting is definately the product of some cringe viral snowball effect of the also rather benign p2pshell vuln.
It feels like there's a ton of AI influencer astroturfing going on, because its wildly easy to get engagement when you add the words "agent/ai" with "vulnerbility" and [insert popular service].
The vast majority of tailnets are just hobbyists on the generous free tier and probably don't use tailscale ssh, but rather ssh over a tailnet. Usually it's either just one person or a family sharing access to the tailnet. But for corporate accounts where ACLs are used for SSH yeah this is big.
Why does your comment here contain more information than the blog post from tailscale itself?
I backup my different devices to my NAS. The user is a restricted backup user seeing only their own directory. I obviously don't want my torrent computer gets root on my NAS.
I personally use openssh, but someone else may use tailscale SSH.
I think this does downplay the vulnerability, since it assumes that teams using tailscale SSH have a lax security posture. I would hope that a security conscious team has accounts with least privilege available i.e. no root access. Please don't discount this critical vulnerability.
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