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.
https://support.apple.com/kb/HT205033
https://support.apple.com/kb/HT205030
http://www.ubuntu.com/usn/USN-2937-1
http://www.securitytracker.com/id/1033274
http://www.securityfocus.com/bid/76341
http://lists.opensuse.org/opensuse-updates/2016-03/msg00132.html
http://lists.apple.com/archives/security-announce/2015/Aug/msg00002.html
http://lists.apple.com/archives/security-announce/2015/Aug/msg00000.html