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.
Thank you for your work 🙏
Good job. I don’t understand very much of that, so that makes me all the more grateful. Thank you.
what steps are being taken to ensure it doesn’t happen again? was any personal data compromised for users?
Also I am curious, what’s the easiest way to currently reach the admins in case this happens again somehow? Two of them on their account have been seemingly inactive for a month and as per your own statement you rarely check your notifications and dms. Is there a discord somewhere for it?
Mail: info@lemmy.world Mastodon: @mwadmin@mastodon.world Matrix: https://matrix.to/#/#lemmy-support-general:discuss.online
They defaced it with dicks and changed the federation list to be only threads.net. I don’t think it was a state sponsored chinese hacking group. :)
So all our cookies are negated now with the JWT changed, and we just needed to login again? Can attackers have stolen our cookies in order to use our accounts to post as if it was us? I’m sure they were only interested in admin cookies, so most others were “useless” to them? I see nothing wrong with my posts so I should be safe, right?
If you think they could change your password:
YES, they could.
They could have changed the email => “Forgot PW” and with that you lost ur account.
the details of the vulnerability are already known now anyway since there’s a fix that was proposed on the Lemmy GitHub so I don’t think it will hurt others to talk about it
https://github.com/LemmyNet/lemmy-ui/pull/1897/files found it myself
yup that’s the one
what I find weird is that the “fix” still focuses only on the front-end, the issue is still that unescaped HTML is being stored in the database and still trusting the front-end is nuts
Thanks for your efforts. I know that Lemmy was put in place rather quickly as a Reddit alternative. But I’m genuinely hopeful that this will be a good alternative.
