Description
Mastodon is a free, open-source social network server based on ActivityPub. In Mastodon version 4.4, support for verifiable quote posts with quote controls was added, but it is possible for an attacker to bypass these controls in Mastodon versions prior to 4.4.8 and 4.5.0-beta.2. Mastodon internally treats reblogs as statuses. Since they were not special-treated, an attacker could reblog any post, then quote their reblog, technically quoting themselves, but having the quote feature a preview of the post they did not get authorization for with all of the affordances that would be otherwise denied by the quote controls. This issue has been patched in versions 4.4.8 and 4.5.0-beta.2.
Problem types
CWE-754: Improper Check for Unusual or Exceptional Conditions
Product status
= 4.5.0-beta.1
References
github.com/...stodon/security/advisories/GHSA-8h43-rcqj-wpc6
github.com/...ommit/2dc4552229b55e2e4adaef675e68ed7ae123d78e
github.com/...ommit/405a49df44033e7d179f3d44d59fb68a67d54789
github.com/mastodon/mastodon/releases/tag/v4.4.8
github.com/mastodon/mastodon/releases/tag/v4.5.0-beta.2
