It was discovered that Kerberos did not correctly handle invalid AES blocks. An unauthenticated remote attacker could send specially crafted traffic that would crash the KDC service, leading to a denial of service, or possibly execute arbitrary code with root privileges.
The problem can be corrected by updating your system to the following package versions:
12 January 2010
A security issue affects these releases of Ubuntu and its derivatives:
It was discovered that Kerberos did not correctly handle invalid AES blocks. An unauthenticated remote attacker could send specially crafted traffic that would crash the KDC service, leading to a denial of service, or possibly execute arbitrary code with root privileges.
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 upgrade is sufficient to effect the necessary changes.