A session fixation issue was discovered in the NGINX OpenID Connect reference implementation, where a nonce was not checked at login time. This flaw allows an attacker to fix a victims session to an attacker-controlled account. As a result, although the attacker cannot log in as the victim, they can force the session to associate it with the attacker-controlled account, leading to potential misuse of the victims session.
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 |
|---|---|---|---|
| Nginx_api_connectivity_manager | F5 | 1.3.0 (including) | 1.9.3 (excluding) |
| Nginx_ingress_controller | F5 | * | 1.12.5 (including) |
| Nginx_ingress_controller | F5 | 2.2.1 (including) | 2.4.2 (including) |
| Nginx_ingress_controller | F5 | 3.0.0 (including) | 3.7.1 (excluding) |
| Nginx_instance_manager | F5 | 2.5.0 (including) | 2.17.4 (excluding) |
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.