Ubuntu 12.04 LTS USN-1828-1 Critical: Kernel Privilege Escalation

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 12.04 LTS:
  linux-image-3.5.0-30-generic    3.5.0-30.51~precise1

After a standard system update you need to reboot your computer to make
all the necessary changes.

ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed. If
you use linux-restricted-modules, you have to update that package as
well to get modules which work with the new kernel version. Unless you
manually uninstalled the standard kernel metapackages (e.g. linux-generic,
linux-server, linux-powerpc), a standard system upgrade will automatically
perform this as well.