Incorrect authorization in the "submitted together" feature in Gerrit versions 2.12 and later allows an authenticated attacker with force push permissions on a secondary branch to bypass code review and forcefully submit code to restricted branches via a crafted submission matching the "topic" tag of an unapproved change.
Any git operation is passed through Jetty and a session is created. No expiry is set for the session and Jetty does not automatically dispose of the session. Over multiple git actions, this can lead to a heap memory exhaustion for Gerrit servers. We recommend upgrading Gerrit to any of the versions listed above.