CVE-2014-1295 (Apple's Secure Transport and Triple Handshake Attack)
The attacker acts as a man-in-the-middle and can forward the clients nonce to the server and the servers nonce to the client. As a result both parties establish a connection with the attacker using the same nonces. 

Because of a weakness in the TLS protocol, the two connections can have the same key, and this key is known to the attacker.

After resumption TLS 'forgets' that the connections were established with the attacker, and did not prevent renegotiation, e.g. using client authentication, between two honest participants. This is corrected by the patch that requires a renegotiation to present the same server certificate as was presented in the original connection.