CVE-2024-3596

El protocolo RADIUS según RFC 2865 es susceptible a ataques de falsificación por parte de un atacante local que puede modificar cualquier respuesta válida (acceso-aceptación, acceso-rechazo o acceso-desafío) a cualquier otra respuesta utilizando un ataque de colisión de prefijo elegido contra la firma del autenticador de respuesta MD5. .

A vulnerability in the RADIUS (Remote Authentication Dial-In User Service) protocol allows attackers to forge authentication responses when the Message-Authenticator attribute is not enforced. This issue arises from a cryptographically insecure integrity check using MD5, enabling attackers to spoof UDP-based RADIUS response packets. This can result in unauthorized access by modifying an Access-Reject response to an Access-Accept response, thereby compromising the authentication process.

Goldberg, Miro Haller, Nadia Heninger, Mike Milano, Dan Shumow, Marc Stevens, and Adam Suhl discovered that FreeRADIUS incorrectly authenticated certain responses. An attacker able to intercept communications between a RADIUS client and server could possibly use this issue to forge responses, bypass authentication, and access network devices and services. This update introduces new configuration options called "limit_proxy_state" and "require_message_authenticator" that default to "auto" but should be set to "yes" once all RADIUS devices have been upgraded on a network.