Several security issues were fixed in the kernel.
Vasily Averin discovered that the NFS Lock Manager (NLM) incorrectly handled unlock requests. A local attacker could exploit this to cause a denial of service. (CVE-2011-2491)
3 December 2011
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in the kernel.
Vasily Averin discovered that the NFS Lock Manager (NLM) incorrectly handled unlock requests. A local attacker could exploit this to cause a denial of service. (CVE-2011-2491)
Robert Swiecki discovered that mapping extensions were incorrectly handled. A local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2011-2496)
It was discovered that the wireless stack incorrectly verified SSID lengths. A local attacker could exploit this to cause a denial of service or gain root privileges. (CVE-2011-2517)
Ben Pfaff discovered that Classless Queuing Disciplines (qdiscs) were being incorrectly handled. A local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2011-2525)
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
After a standard system update you need to reboot your computer to make all the necessary changes.