2014-04-16: Advisory - WinSCP

WinSCP is not checking the "Common Name" of a X.509 certificate, when FTP with TLS is used. 

A user can not recognize an easy to perform man-in-the-middle attack, because the client does not validate the "Common Name" of the servers X.509 certificate. In networking environment that is not trustworthy, like a wifi network, using FTP AUTH TLS with WinSCP the servers identity can not be trusted. For more information on the security weakness check Micha Borrmann's advisory.