GHSA-gccq-h3xj-jgvf: Pixelfed doesn't check OAuth Scopes in API routes, giving elevated permissions

Summary

When processing requests authorization was improperly and insufficiently checked, allowing attackers to access far more functionality than users intended, including to the administrative and moderator functionality of the Pixelfed server.

This vulnerability affects every version of Pixelfed between v0.10.4 and v0.11.9, inclusive. A proof of concept of this vulnerability exists.

Details

TBA. This advisory will be edited with more details on 2024/02/25, 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.

Impact

This vulnerability affects every local user of a Pixelfed server, and can potentially affect the servers’ ability to federate.

Some user interaction is required to setup the conditions to be able to exercise the vulnerability, but the attacker could conduct this attack time-delayed manner, where user interaction is not actively required.

References

• GHSA-gccq-h3xj-jgvf
• pixelfed/pixelfed@7e47d6d
• pixelfed/pixelfed@fd7f5dbb
• pixelfed/pixelfed@fd7f5db