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. Because not all instances are aware, we will not go into detail on the
vulnerability yet. 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.
I’ve checked the admin activity, the logs - nothing suspicious.
I’ve also found the description of the vulnerability - it was an XSS attack abusing custom emojis.
I have never added any. I have also checked the database and there are no custom emojis on this instance. Everything appears to be fine for now. Will update to the fixed release as soon as it’s available.
Thanks a lot for your prompt response!
Explanation of vulnerability