The remote host is missing an update to samba announced via advisory USN-680-1.
Details follow:
It was discovered that Samba did not properly perform bounds checking in certain operations. A remote attacker could possibly exploit this to read arbitrary memory contents of the smb process, which could contain sensitive infomation or possibly have other impacts, such as a denial of service.
Solution: The problem can be corrected by upgrading your system to the following package versions:
Ubuntu 8.10: samba 2:3.2.3-1ubuntu3.3
In general, a standard system upgrade is sufficient to effect the necessary changes.