The extensions APIs in the kernel in Apple iOS before 6.0.1 provide kernel addresses in responses that contain an OSBundleMachOHeaders key, which makes it easier for remote attackers to bypass the ASLR protection mechanism via a crafted app.
http://www.securityfocus.com/bid/56361
http://support.apple.com/kb/HT5598
http://support.apple.com/kb/HT5567
http://secunia.com/advisories/51445
http://lists.apple.com/archives/security-announce/2013/Mar/msg00002.html
http://lists.apple.com/archives/security-announce/2012/Nov/msg00000.html
http://archives.neohapsis.com/archives/bugtraq/2012-11/0012.html