Lemmy.world and other instances hacked - LemmyWorld
lemmy.world
A number of Lemmy instances have been hacked overnight. Some may remain inaccessible until they have been secured and restarted. As a safety precaution logged-on sessions on many servers have been cancelled and you are required to logon again. Unfortunately, the only way I could find to do this in Liftoff! is by going to Settings > Accounts and deleting each local account by long pressing on it, and then create it again. All your posts, comments and bookmarks should be preserved during this process. Please see the linked posts for further details as they emerge. Thanks all, and please bear with us as this gets resolved.

Drawing attention on this instance so Admins are aware and can address the propagating exploit.

EDIT: Found more info about the patch.

A more thorough recap of the issue.

GitHub PR fixing the bug: https://github.com/LemmyNet/lemmy-ui/pull/1897/files

If your instance has custom emojis defined, this is exploitable everywhere Markdown is available. It is NOT restricted to admins, but can be used to steal an admin’s JWT, which then lets the attacker get into that admin’s account which can then spread the exploit further by putting it somewhere where it’s rendered on every single page and then deface the site.

If your instance doesn’t have any custom emojis, you are safe, the exploit requires custom emojis to trigger the bad code branch.

  • FBelaza@lemm.eeEnglish
    50·
    1 year ago

    I’m greatly surprised how Lemmy and the fediverse society has responded with this. The bug was found yesterday, maybe? And I’ve read about it three, four times (in different servers); a temporal solution was published in hours and it’s already patched on the repo.

    Another victory for Open Source and the Fediverse in general.

    • cakeistheanswer@lemmy.fmhy.mlEnglish
      24·
      1 year ago

      More importantly the issue was tracked and resolved publicly.

      The issue of trust in corporate spaces gets used to bury these things, this is a good model on how to restore it in the open.

    • kryllic@programming.devEnglish
      2·
      1 year ago

      I firmly believe open source is the future of software development and things like this really show off the strengths of this sort of collaborative work. Everyone benefits and it’s a great way to maintain high quality.