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.

  • j4k3@lemmy.world
    2·
    1 year ago

    The same thing was required with Vanadium. In the past, issues with the site only required clearing the cache. However, this one requires clearing the cache and cookies.

    • Rob T Firefly@lemmy.worldEnglish
      2·
      1 year ago

      Clearing cache and cookies alone didn’t work for me, the login button just wasn’t working after I typed the password in. I ended up doing a password reset, opening the reset link in a private/incognito browser window and choosing a new password, and then my new password worked to log me in with my normal browser window.

    • Aceticon@lemmy.world
      2·
      1 year ago

      I didn’t actually clean the cache, only the cookies.

      Unless the force reload (i.e. pressing shift + clicking the reload icon) cleans the cache.

      I actually tried the most minimal clearing possible (because having to re-login for all the other things in other pages and tabs on the browser is a PITA) and so only cleaned the cookies from the lemmy.world domain and then did a shift-reload of the lemmy.world page only.