WKWebView in WebKit in Apple iOS before 10, iTunes before 12.5.1 on Windows, and Safari before 10 does not properly verify X.509 certificates from HTTPS servers, which allows man-in-the-middle attackers to spoof servers and obtain sensitive information via a crafted certificate.
https://support.apple.com/HT207158
https://support.apple.com/HT207157
https://support.apple.com/HT207143
http://www.securitytracker.com/id/1036854
http://www.securityfocus.com/bid/93066
http://lists.apple.com/archives/security-announce/2016/Sep/msg00012.html
http://lists.apple.com/archives/security-announce/2016/Sep/msg00008.html
http://lists.apple.com/archives/security-announce/2016/Sep/msg00007.html