The net_ctl_permissions function in net/sysctl_net.c in the Linux kernel before 3.11.5 does not properly determine uid and gid values, which allows local users to bypass intended /proc/sys/net restrictions via a crafted application.
https://github.com/torvalds/linux/commit/2433c8f094a008895e66f25bd1773cdb01c91d01
https://bugzilla.redhat.com/show_bug.cgi?id=1027752
http://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.11.5
http://www.ubuntu.com/usn/USN-2049-1