CFNetwork in Apple iOS before 10, OS X before 10.12, tvOS before 10, and watchOS before 3 misparses the Set-Cookie header, which allows remote attackers to obtain sensitive information via a crafted HTTP response.
https://support.apple.com/HT207170
https://support.apple.com/HT207143
https://support.apple.com/HT207142
https://support.apple.com/HT207141
http://www.securitytracker.com/id/1036858
http://www.securityfocus.com/bid/93054
http://lists.apple.com/archives/security-announce/2016/Sep/msg00011.html
http://lists.apple.com/archives/security-announce/2016/Sep/msg00010.html
http://lists.apple.com/archives/security-announce/2016/Sep/msg00008.html
http://lists.apple.com/archives/security-announce/2016/Sep/msg00006.html