Description

This detector checks whether a web server refuses connections that only offer Perfect Forward Secrecy (PFS) cipher suites. PFS is a critical security feature that ensures past communications remain secure even if the server's private key is compromised in the future. A server that refuses PFS-only connections may force clients to use less secure cipher suites.

Detection Strategy

• Connect to the server and attempt TLS handshakes for each supported TLS version (except TLS 1.3)

• Send a ClientHello message offering only cipher suites that support Perfect Forward Secrecy (DHE, ECDHE, SRP, ECCPWD)

• A vulnerability is reported if the server explicitly rejects the connection with an alert instead of selecting one of the offered PFS cipher suites

• Each TLS version that results in a connection rejection is included in the vulnerability report