CFNetwork in Apple Mac OS X 10.6.3 and 10.6.4 supports anonymous SSL and TLS connections, which allows man-in-the-middle attackers to redirect a connection and obtain sensitive information via crafted responses.
http://support.apple.com/kb/HT4312
http://securitytracker.com/id?1024359
http://lists.apple.com/archives/security-announce/2010//Aug/msg00003.html