Update: Federation and community creation are now back online!
Hey all, there’s a hack floating around which spreads via federated comments and steals users’ Lemmy auth tokens. Lemmy.world and other large instances have been hacked, so we’re taking some precautions until this is fixed:
- We’re logging everyone out so that auth tokens reset
- We’re closing off federation and community creation until this is patched
FYI, there are no indications that anyone on our instance has been hacked. We did find ten comments with the code injection attack, which we’ve now scrubbed. But it’s very unlikely that this will cause harm at this stage. There are several steps between this and hacking the entire instance. (Also FYI for nontechnical users, the hack affected Lemmy logins and nothing else. Web browsers run all websites in a kind of “jail”)
Sorry for the inconvenience – growing pains. Updates to come as we learn more!
Thank you. I was bewildered by the earlier announcement but you have laid it out a lot clearer here.
I’m sorry if my statement cause you any confusion (シ_ _)シ
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I’d prefer not to until we install a patch, since the exploit seems viral in nature (compromise one instance, use that to compromise the next, etc). So trusting one is like trusting all
We’re testing that in dev so we might refederate later tonight. Or maybe tomorrow
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Yep! It’s a really obvious one, just escape a bit of user / federation-facing input that wasn’t being escaped. 5-10 lines of code or something.
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No wonder I couldn’t see the posts from here today from my instance. Anyway RC2 is out, which should fix this XSS vulnerability
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Wouldn’t be too fussed about it tbh, can never play it too safe when it comes to such incidents.
edit-mmm still can’t see the posts here from my instance, sadge
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Thanks for the heads-up! We’ve given it a reboot and things seem to be working as intended now. In general I have a weekly crunch period which happens around Tue-Thu so I go into low availability, and catch up on the weekend – always welcome to try other admins! Naomi is on technical too :)
Re: Defederation / allowlist: I’m quite sure a lot of instances defederated actually! I believe I read a note on this on a github discussion, or on a lemmy.ml post. IMO if there’s an active security hole which appears to be spreadable to other instances via federation feeds, there is no reasonable basis on which we can decide to trust external instances. Without a patch, they can become infected at any time. I could be missing an angle, but I still feel full defederation was the right call. Happy to hear the arguments against!
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Ah, didn’t realize there’s a site sticky. Sorry about the other post. Everyone pening dealing with this ig. Sucks to not be on PC.
Still not sure if comments loaded from other instances with custom emoji (the vector of this exploit) can trigger the exploit here, but since we defederated there shouldn’t be a way for it to get in, I hope.