While I was asleep, apparently the site was hacked. Luckily, (big) part of the lemmy.world team is in US, and some early birds in EU also helped mitigate this.

As I am told, this was the issue:

  • There is an vulnerability which was exploited
  • Several people had their JWT cookies leaked, including at least one admin
  • Attackers started changing site settings and posting fake announcements etc

Our mitigations:

  • We removed the vulnerability
  • Deleted all comments and private messages that contained the exploit
  • Rotated JWT secret which invalidated all existing cookies

The vulnerability will be fixed by the Lemmy devs.

Details of the vulnerability are here

Many thanks for all that helped, and sorry for any inconvenience caused!

Update While we believe the admins accounts were what they were after, it could be that other users accounts were compromised. Your cookie could have been ‘stolen’ and the hacker could have had access to your account, creating posts and comments under your name, and accessing/changing your settings (which shows your e-mail).

For this, you would have had to be using lemmy.world at that time, and load a page that had the vulnerability in it.

  • kill
    5•1 year ago

    1 - jwt is the authentication cookie u get when u sign in with ur password, ur browser stores the jwt and then any further interaction authenticates using it

    2 - yes, userscripts, extensions, custom frontends, apps, all apps have access to jwt

    • key
      3•1 year ago

      2 - yes, userscripts, extensions, custom frontends, apps, all apps have access to jwt

      HttpOnly flag not being set? That would protect against userscript, web apps, and extensions without extended permissions being able to access it.