An issue has been discovered in GitLab affecting all versions starting from 11.9 before 15.9.6, all versions starting from 15.10 before 15.10.5, all versions starting from 15.11 before 15.11.1. The condition allows for a privileged attacker, under certain conditions, to obtain session tokens from all users of a GitLab instance.
Authenticating a user, or otherwise establishing a new user session, without invalidating any existing session identifier gives an attacker the opportunity to steal authenticated sessions.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Gitlab | Gitlab | 11.9 (including) | 15.9.6 (excluding) |
| Gitlab | Gitlab | 15.10 (including) | 15.10.5 (excluding) |
| Gitlab | Gitlab | 15.11 (including) | 15.11.1 (excluding) |
| Gitlab | Ubuntu | esm-apps/xenial | * |
| Gitlab | Ubuntu | trusty | * |
| Gitlab | Ubuntu | xenial | * |
Such a scenario is commonly observed when:
In the generic exploit of session fixation vulnerabilities, an attacker creates a new session on a web application and records the associated session identifier. The attacker then causes the victim to associate, and possibly authenticate, against the server using that session identifier, giving the attacker access to the user’s account through the active session.