cross-posted from: https://sh.itjust.works/post/923025
lemmy.world is a victim of an XSS attack right now and the hacker simply injected a JavaScript redirection into the sidebar.
It appears the Lemmy backend does not escape HTML in the main sidebar. Not sure if this is also true for community sidebars.
This has nothing to do with XSS, it is a simple HTML injection vulnerability, and it can only be exploited by instance admins.
Also Lemmy.world appears to have been running a custom frontend so it’s hard to say how widespread the affects of this are.
Worst case scenario, they can steal your Lemmy session, right?
Which isn’t super bad for a service like Lemmy. This isn’t a social network, so most contact list scams would be useless.
Edit: just read the targets were admins. That IS bad.