A Linux kernel security vulnerability was recently discovered in the Linux kernel, affecting all the Ubuntu 11.10 (Oneiric Ocelot) operating system.
Vasiliy Kulikov discovered CVE-2011-2494, a Linux kernel vulnerability that allows a local attacker to read various information on the system, leading to loss of privacy, because taskstats didn't enforce access restrictions.
This security flaw can be fixed if you update your Ubuntu 11.10 (Oneiric Ocelot) system to the linux-image-3.0.0-13 (3.0.0-13.22) kernel package. Run the Software Update app to do that and 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 which work with the new Linux kernel version.