Mastodon security update: every version prior to today's is vulnerable to remote user impersonation and takeover

Atelopus-zeteki , 5 months ago

Hmm, so if one is on iOS, the current version 2023.16, and is vulnerable. Take note apple / mac folx.

cypherpunks OP , 5 months ago

No, this is a server-side vulnerability. Clients do not need to update, instances do.

Atelopus-zeteki , 5 months ago

TY!

steter , 5 months ago

@cypherpunks Upgrading went smoothly.

AngieStone , 5 months ago

@cypherpunks
German news:
https://www.heise.de/news/Mastodon-Diebstahl-beliebiger-Identitaeten-im-foederierten-Kurznachrichtendienst-9615961.html?wt_mc=sm.red.ho.mastodon.mastodon.md_beitraege.md_beitraege

androidul , 4 months ago

nett hier

redcalcium , 5 months ago

This advisory will be edited with more details on 2024/02/15, when admins have been given some time to update, as we think any amount of detail would make it very easy to come up with an exploit.

But the commit to fix insufficient origin validation is already visible right there in the repo?

pelespirit , 5 months ago

Could you explain what you're saying in common language?

cypherpunks OP , 5 months ago

The lack of details in the advisory is only a minor impediment for a malicious person who wants to figure out how to implement their own exploit for this vulnerability. Anyone can read the patch that fixes it and figure it out.

TLDR: if you run your own instance, update it ASAP. If an instance you rely on hasn't updated yet, consider asking its admins to do so. And if they don't update it soon, you might want to reconsider your choice of instance.

elvith , 5 months ago

And if they don't update it soon, you might want to reconsider your choice of instance.

The advisory went up about 4h ago. About 3h ago, my instance admin sent out an announcement that the patch had been applied. That was before I even heard about the issue.

Nice work :)

losttourist , 5 months ago

Without a published POC there's a slightly longer window before clueless script kiddies start having a go at exploiting the vulnerability, though.

fartsparkles , 5 months ago

Script kiddies aren’t the first ones to take advantage of vulns, threat actors are.

jmcs , 5 months ago

That doesn't mean you shouldn't try to contain the blast radius.

fartsparkles , 5 months ago

[Thread, post or comment was deleted by the author]

cheviotveneer , 5 months ago

private repo they commit to and build from

This isn't possible with Ruby and Mastodon. The only way to distribute the patch is to reveal the changes to the source. FWIW, compiling the fix is still just an obfuscation method, one can still just diff the binaries and see what changed (see: reverse-engineering Windows vulnerabilities in updates).

At best, you can release it with a bunch of unrelated and obfuscating changes, but putting work into doing that is further delaying simply getting the fix released.

desmosthenes , 5 months ago

hope for the best; plan for the worst