Volker Lendecke discovered that Samba incorrectly handled certain file descriptors. A remote attacker could send a specially crafted request to the server and cause Samba to crash or hang, resulting in a denial of service.
The problem can be corrected by updating your system to the following package versions:
28 February 2011
A security issue affects these releases of Ubuntu and its derivatives:
Volker Lendecke discovered that Samba incorrectly handled certain file descriptors. A remote attacker could send a specially crafted request to the server and cause Samba to crash or hang, 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.