The Content Security Policy implementation in WebKit in Apple Safari before 6.2.8, 7.x before 7.1.8, and 8.x before 8.0.8, as used in iOS before 8.4.1 and other products, does not properly restrict cookie transmission for report requests, which allows remote attackers to obtain sensitive information via vectors involving (1) a cross-origin request or (2) a private-browsing request.
lists.apple.com/archives/security-announce/2015/Aug/msg00000.html
lists.apple.com/archives/security-announce/2015/Aug/msg00002.html
lists.opensuse.org/opensuse-updates/2016-03/msg00132.html
www.securityfocus.com/bid/76341
www.securitytracker.com/id/1033274
www.ubuntu.com/usn/USN-2937-1
support.apple.com/kb/HT205030
support.apple.com/kb/HT205033