Hi all,
If you’re just now signing in for the first time in 12+ hours, you may just now be finding out that Lemmy World and other instances where hijacked. The hijackers had the full abilities of hijacked user, mod, and admin accounts. At this time, I am only aware of instance defacing and URL redirections to have been done by the hijackers.
If you were not forced to sign back in this morning, contact your instance admin to verify mitigations were completed on your instance.
How?
This occurred due to an XSS attack in the recently added custom emojis. Instance admins should follow the issue tracker on the LemmyNet GitHub, as well as the Matrix Chat. Post-Incident Activity is still on-going.
Currently, it is likely that just your session cookie was stolen, with instance admins being targeted specifically by checking for navAdmin, an HTML element only instance admins had. I do not believe this to affect users across instances, but I have yet to confirm this.
What happens next?
As I am not the developers or affected instance admins, I cannot make any guarantees. However, here is what you’ll likely see:
- Post Incident investigation continues. This will include inspecting code, posts, websites, and more used by the hijackers. An official incident writeup may occur. You should expect the following from that report:
- Exactly what happened, when.
- The incident response that occurred from instance admins
- Information that might have helped resolve the issue sooner
- Any issues that prevented successful resolution
- What should have been done differently by admins
- What should be improved by developers
- What can be used to identify the next attack
- What tools are needed to identify that information
-
A CVE is created. This is an official alert of the issue, and notifies security experts (and enthusiasts), even those not using lemmy, about the issue.
-
A code security audit is done. This will likely just be casual reviews by technical lemmy users. However, I will be reaching out to the Mozilla Foundation and Cure53 as they recently did an audit of Mastodon. If there is interest in an external audit of lemmy and the costs are affordable, I’ll look into crowdfunding this cost.
It could get VERY, VERY expensive… depends on code complexity.
This one’s better… and simpler 👍.
Yeah, specifically why I mentioned “affordable”.
is there a mailing list or anything like that? i would like to help contribute to security hardening efforts
They have a Matrix chatroom I believe.
There’s this dev chatroom https://matrix.to/#/#lemmydev:matrix.org
Not at this stage.
Lemmy grew too fast, got many more eyes.
Step 1 is getting a security focus group selected from the people who contribute code to lemmy.
Just like the admins and coders volonteer their time, security specialists will too, money might be needed, but that is not in the the first steps.
Agreed, this is wise.
Agreed. It might be hard to swing right now, but imo this is going to be a crucial step moving forward.
The examples below might actually do most of the work for free.