SChannel in Microsoft Windows Vista SP2 Windows Server 2008 SP2 and R2 SP1 Windows 7 SP1 Windows 8 Windows 8.1 Windows Server 2012 Gold and R2 and Windows RT Gold and 8.1 lacks the required extended master-secret binding support to ensure that a server's X.509 certificate is the same during renegotiation as it was before renegotiation which allows man-in-the-middle attackers to obtain sensitive information or modify TLS session data via a \triple handshake attack \ aka \Schannel TLS Triple Handshake Vulnerability.\