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.

      • 0x4E4F
        2·
        1 year ago

        Clear cache and data in the browser. You don’t have to clear everything, just everything related to lemmy.world.

      • Favrion@lemmy.world
        1·
        1 year ago

        I also can’t post in some communities in the app and have to go to the desktop for that.

        • 0x4E4F
          2·
          1 year ago

          That might be something introduced after the attack, might even be code changes. It should be fixed within a few days, I’m sure the admin team is working on bringing everything back to normal. If it’s not fixed within a few days, clear cache and data in liftoff, readd your accounts.