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.
Was wondering this myself. Is there a way for users who where exposed to know about it?
(Edit) Eg if the exploit was through a post get notified if they saw the post?
apparently they posted it as a weird image or emoji that looked like this:
HOLY SHIT I LUCKED OUT LMAO, I ALMOST CLICKED ON THAT EARLIER
no need for clicking. if you saw it, it did execute code that stole your cookie (atleast on desktop…dunno about how it is in apps). they tried to steal admin accounts wirh that.
There is no need to get notified, they didn’t steal passwords, just session cookies. Most (all?) servers have invalidated all the user login cookies, but if you are in doubt, just logging out and back in should be enough to get a new cookie.