The remote host is missing an update to linux-source-2.6.12 announced via advisory USN-319-2.
A security issue affects the following Ubuntu releases:
Ubuntu 5.04 Ubuntu 5.10
This advisory also applies to the corresponding versions of Kubuntu, Edubuntu, and Xubuntu.
USN-319-1 fixed a Linux kernel vulnerability in Ubuntu 6.06 LTS. This followup advisory provides the corresponding updates for Ubuntu 5.04 and 5.10.
For reference, these are the details of the original USN:
A race condition has been discovered in the file permission handling of the /proc file system. A local attacker could exploit this to execute arbitrary code with full root privileges.
Solution: The problem can be corrected by upgrading your system to the following package versions: