The Certificate UI in Apple iOS before 8.4.1 does not prevent X.509 certificate acceptance within the lock screen, which allows physically proximate attackers to establish arbitrary certificate trust relationships by completing a dialog.
https://support.apple.com/kb/HT205030
http://www.securitytracker.com/id/1033275
http://www.securityfocus.com/bid/76337
http://lists.apple.com/archives/security-announce/2015/Aug/msg00002.html