dyld in Dev Tools in Apple iOS before 9 allows attackers to execute arbitrary code in a privileged context or cause a denial of service (memory corruption) via a crafted app.
http://lists.apple.com/archives/security-announce/2015/Sep/msg00001.html
http://lists.apple.com/archives/security-announce/2015/Sep/msg00005.html
http://lists.apple.com/archives/security-announce/2015/Sep/msg00008.html
http://www.securityfocus.com/bid/76764
http://www.securitytracker.com/id/1033609
https://support.apple.com/HT205212