The WebKit Canvas implementation in Apple iOS before 9 allows remote attackers to bypass the Same Origin Policy and obtain sensitive image information via vectors involving a CANVAS element.
lists.apple.com/archives/security-announce/2015/Sep/msg00001.html
lists.apple.com/archives/security-announce/2015/Sep/msg00007.html
lists.opensuse.org/opensuse-updates/2016-03/msg00132.html
www.securityfocus.com/bid/76766
www.securitytracker.com/id/1033609
www.ubuntu.com/usn/USN-2937-1
support.apple.com/HT205212
support.apple.com/HT205265