Vasiliy Kulikov, a security resercher recently discovered vulnerability in the Linux kernel, affecting all the Ubuntu 11.10 (Oneiric Ocelot) operating system. 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.
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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 reboot the system.