The H2-DM1E PLCs authentication protocol appears to utilize either a custom encoding scheme or a challenge-response protocol. However, theres an observed anomaly in the H2-DM1E PLCs protocol execution, namely its acceptance of multiple distinct packets as valid authentication responses. This behavior deviates from standard security practices where a single, specific response or encoding pattern is expected for successful authentication.
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.
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.