The Berkeley Packet Filter (BPF) interpreter implementation in the kernel in Apple iOS before 6 accesses uninitialized memory locations, which allows local users to obtain sensitive information about the layout of kernel memory via a crafted program that uses a BPF interface.
https://exchange.xforce.ibmcloud.com/vulnerabilities/78724
http://support.apple.com/kb/HT5503
http://lists.apple.com/archives/security-announce/2012/Sep/msg00003.html