All Ubuntu 13.04 users are urged to update their systems as soon as possible!
Canonical announced last evening, September 5, in a security notice, that a new Linux kernel update is now available for its Ubuntu 13.04 (Raring Ringtail) operating system, fixing six security vulnerabilities discovered by various developers in the Linux kernel packages.These are the six kernel vulnerabilities concerning the Ubuntu 13.04 (Raring Ringtail) operating system: CVE-2013-1060, CVE-2013-2140, CVE-2013-2232, CVE-2013-2234, CVE-2013-4162, and CVE-2013-4163.
You can click on each one to see how it affects your system, or go here for in-depth descriptions, as it affects other Linux operating systems as well.
The security flaws can be fixed if you upgrade your system(s) to the linux-image-3.8.0-30 (3.8.0-30.44) package(s). To apply the update, run the Update Manager application or follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
Don't forget to reboot your computer after the upgrade!