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.

  • Nugget@lemmy.world
    271·
    1 year ago

    I think this is a strong reminder: We shouldn’t put all our eggs in one basket. This will happen again. Unlike Reddit, we don’t need to concentrate all communities on one instance. We should all make an effort to spread out. Some other general use instances are:

    Again, for those new, you can post content to any of these instances and interact with content from other instances at the same time, just like you can send an email from your Gmail account to your ProtonMail account.

    • dragontamer@lemmy.worldEnglish
      4·
      1 year ago

      The malicious Javascript was in a post however, and that post spread to all Lemmies that saw the post.

      I’m pretty sure all web browsers who saw that post passed the JWT cookie to the hacker. The hacker was looking for admin accounts and got the Lemmy.world admin first.

    • solarbabies@lemmy.world
      1·
      1 year ago

      Did any of the other instances suffer this vulnerability? Or are they all running different code? i.e. different repositories/implementations of Lemmy