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.ee
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    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.ml
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      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.dev
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      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.