The CFNetwork HTTPProtocol component in Apple iOS before 9 allows remote attackers to bypass the HSTS protection mechanism, and consequently obtain sensitive information, via a crafted URL.
http://lists.apple.com/archives/security-announce/2015/Sep/msg00001.html
http://lists.apple.com/archives/security-announce/2015/Sep/msg00008.html
http://www.securityfocus.com/bid/76764
http://www.securitytracker.com/id/1033609