net/xfrm/xfrm_user.c in the Linux kernel before 3.6 does not initialize certain structures, which allows local users to obtain sensitive information from kernel memory by leveraging the CAP_NET_ADMIN capability.
https://www.kernel.org/pub/linux/kernel/v3.x/patch-3.6.bz2
https://github.com/torvalds/linux/commit/f778a636713a435d3a922c60b1622a91136560c1
https://github.com/torvalds/linux/commit/7b789836f434c87168eab067cfbed1ec4783dffd
https://github.com/torvalds/linux/commit/1f86840f897717f86d523a13e99a447e6a5d2fa5
http://www.ubuntu.com/usn/USN-1798-1
http://www.ubuntu.com/usn/USN-1792-1
http://www.openwall.com/lists/oss-security/2013/03/05/13