The TLS Handshake Protocol implementation in Secure Transport in Apple OS X before 10.11 accepts a Certificate Request message within a session in which no Server Key Exchange message has been sent, which allows remote attackers to have an unspecified impact via crafted TLS data.
https://support.apple.com/HT205267
http://www.securitytracker.com/id/1033703
http://www.securityfocus.com/bid/76908
http://lists.apple.com/archives/security-announce/2015/Sep/msg00008.html