Apple iOS before 8 does not follow the intended configuration setting for text-message preview on the lock screen, which allows physically proximate attackers to obtain sensitive information by reading this screen.
https://exchange.xforce.ibmcloud.com/vulnerabilities/96081
http://www.securitytracker.com/id/1030866
http://www.securityfocus.com/bid/69922
http://www.securityfocus.com/bid/69882
http://support.apple.com/kb/HT6441
http://archives.neohapsis.com/archives/bugtraq/2014-09/0106.html