go-git: Malformed Git object data may cause panics or resource exhaustion

Impact

Several denial-of-service issues were identified in go-git when parsing maliciously crafted Git repository data.

An attacker may craft a malicious .pack, .idx or loose objects that causes an application using an affected version of go-git to panic or consume excessive resources.

This can lead to denial of service in applications that use go-git to clone, fetch, open, or otherwise process untrusted repositories or Git object data.

Exploitation requires the ability to alter read-only files such as .pack or .idx from the local repository's .git/objects/pack/ directory. Alternatively, the user would need to be interacting with a malicious remote server, which is not recommended and exposes users to a broader class of security risks beyond this issue.

Patches

Users should upgrade to a patched version in order to mitigate this vulnerability. Versions prior to v5 are likely to be affected, users are recommended to upgrade to a supported go-git version.

Credits

go-git thanks @kodareef5, @AyushParkara and @N0zoM1z0 for reporting this in four separate reports. 🙇