Users will have to restart the system after the update
A security vulnerability that was discovered in the Linux kernel, affecting the Ubuntu 12.04 LTS (Precise Pangolin) operating system, has been announced by Canonical.Several security issues have been fixed in the kernel. For example, a flaw was discovered in the Linux kernel's uname system call. An unprivileged user could have exploited this flaw to read kernel stack memory.
The security flaws can be fixed if you upgrade your system(s) to the linux-image-3.5.0-22-generic (3.5.0-22.34).
Don't forget to reboot your computer after the upgrade!
ATTENTION: Due to an unavoidable ABI change, the kernel packages have a new version number, which will force you to reinstall and recompile all third-party kernel modules you might have installed. Moreover, if you use the linux-restricted-modules package, you have to update it as well to get modules that work with the new Linux kernel version.