Missing Report of Error Condition Affecting cryptography package, versions [42.0.0,44.0.1)

Affected versions of this package are vulnerable to Missing Report of Error Condition causing server authentication failures to not be detected by clients, due to handshakes not aborting as expected when the SSL_VERIFY_PEER verification mode is set. An attacker could impersonate a legitimate server by performing a MitM attack on TLS and DTLS connections using Raw Public Keys (RPKs).

Note:

1. This is only exploitable if TLS clients explicitly enable RPK use by the server, and the server, likewise, enables sending of an RPK instead of an X.509 certificate chain. The affected clients are those that then rely on the handshake to fail when the server's RPK fails to match one of the expected public keys, by setting the verification mode to SSL_VERIFY_PEER;

2. Clients that enable server-side raw public keys can still find out that raw public key verification failed by calling SSL_get_verify_result(). Those that do, and take appropriate action, are not affected.

• GitHub Commit
• GitHub Commit
• OpenSSL Advisory