Race condition in the App Installation feature in Apple iOS before 8 allows local users to gain privileges and install unverified apps by leveraging /tmp write access.
https://exchange.xforce.ibmcloud.com/vulnerabilities/96085
http://www.securitytracker.com/id/1030866
http://www.securityfocus.com/bid/69936
http://www.securityfocus.com/bid/69882
http://support.apple.com/kb/HT6441
http://archives.neohapsis.com/archives/bugtraq/2014-09/0106.html