On December 6, Canonical published in a security notice details about a Bind vulnerability for its Ubuntu 12.10 (Quantal Quetzal) and Ubuntu 12.04 LTS (Precise Pangolin) operating systems.According to Canonical, Bind could have been made to crash if it received specially-crafted network traffic.
It was discovered that Bind incorrectly handled certain crafted queries when DNS64 was enabled. A remote attacker could have used this flaw to cause Bind to crash, resulting in a denial of service.
For a more detailed description of the security problems, you can visit Canonical's security notification.
Users can simply fix the security flaws by upgrading the operating systems to the latest bind specific to each distribution.
A normal system update, executed with the Update Manager, will implement all the necessary changes. A complete system restart is not necessary.