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.
Just reload the settings page after saving and you’ll see the activation link. Just now enabled 2FA for my account.
Don’t log out! Open private tab and try logging in to test that it works. Lemmy uses SHA-256 TOTP digest which may not work correctly with some authenticators, only generating useless codes.
The interface for TOTP need to be greatly improved as well. I made sure that I had two browsers logged in when I did it because the flow is so hinky. Not having a confirmation process was a bit nerve racking.