It was discovered that Bind incorrectly handled IXFR transfers and dynamic updates while under heavy load when used as an authoritative server. A remote attacker could use this flaw to cause Bind to stop responding, resulting in a denial of service.
The problem can be corrected by updating your system to the following package versions:
23 February 2011
A security issue affects these releases of Ubuntu and its derivatives:
It was discovered that Bind incorrectly handled IXFR transfers and dynamic updates while under heavy load when used as an authoritative server. A remote attacker could use this flaw to cause Bind to stop responding, resulting in a denial of service.
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.
In general, a standard system update will make all the necessary changes.