The Azure Active Directory (AAD) authentication implementation contained multiple weaknesses in its OAuth 2.0 authorization flow that could allow attackers to bypass important security guarantees provided by the protocol. The application used the PHP session identifier (session_id()) as the OAuth state parameter. Because session identifiers are long-lived authentication credentials, exposing them in OAuth redirect URLs could leak valid session tokens through browser history, HTTP Referer headers, reverse proxies, access logs, or third-party infrastructure involved in the authentication flow. If obtained by an attacker, the leaked session identifier could potentially be used for session hijacking. Additionally, the implementation did not regenerate the session identifier after successful authentication, leaving authenticated sessions susceptible to session fixation attacks where an attacker forces a victim to use a known session identifier before login and later reuses that identifi

The Azure Active Directory (AAD) authentication implementation contained multiple weaknesses in its OAuth 2.0 authorization flow that could allow attackers to bypass important security guarantees provided by the protocol. The application used the PHP session identifier (session_id()) as the OAuth state parameter. Because session identifiers are long-lived authentication credentials, exposing them in OAuth redirect URLs could leak valid session tokens through browser history, HTTP Referer headers, reverse proxies, access logs, or third-party infrastructure involved in the authentication flow. If obtained by an attacker, the leaked session identifier could potentially be used for session hijacking. Additionally, the implementation did not regenerate the session identifier after successful authentication, leaving authenticated sessions susceptible to session fixation attacks where an attacker forces a victim to use a known session identifier before login and later reuses that ident...