The msr_open function in arch/x86/kernel/msr.c in the Linux kernel before 3.7.6 allows local users to bypass intended capability restrictions by executing a crafted application as root, as demonstrated by msr32.c.
https://github.com/torvalds/linux/commit/c903f0456bc69176912dee6dd25c6a66ee1aed00
https://bugzilla.redhat.com/show_bug.cgi?id=908693
http://www.openwall.com/lists/oss-security/2013/02/07/12
http://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.7.6
http://lists.opensuse.org/opensuse-security-announce/2013-07/msg00018.html
http://lists.opensuse.org/opensuse-security-announce/2013-04/msg00018.html