An issue was discovered in Barrier before 2.4.0. An attacker can enter an active session state with the barriers component (aka the server-side implementation of Barrier) simply by supplying a client label that identifies a valid client configuration. This label is Unnamed by default but could instead be guessed from hostnames or other publicly available information. In the active session state, an attacker can capture input device events from the server, and also modify the clipboard content on the server.
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 |
|---|---|---|---|
| Barrier | Barrier_project | * | 2.4.0 (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.