Lock Screen in Apple iOS before 7.1.2 does not properly enforce the limit on failed passcode attempts, which makes it easier for physically proximate attackers to conduct brute-force passcode-guessing attacks via unspecified vectors.
http://www.securitytracker.com/id/1030500
http://www.securityfocus.com/bid/68276
http://archives.neohapsis.com/archives/bugtraq/2014-06/0174.html