The remote host is missing an update to dnsmasq announced via advisory USN-627-1.
A security issue affects the following Ubuntu releases:
Ubuntu 8.04 LTS
This advisory also applies to the corresponding versions of Kubuntu, Edubuntu, and Xubuntu.
Details follow:
Dan Kaminsky discovered weaknesses in the DNS protocol as implemented by Dnsmasq. A remote attacker could exploit this to spoof DNS entries and poison DNS caches. Among other things, this could lead to misdirected email and web traffic.
Solution: The problem can be corrected by upgrading your system to the following package versions:
Ubuntu 8.04 LTS: dnsmasq-base 2.41-2ubuntu2.1
After a standard system upgrade you need to restart Dnsmasq to effect the necessary changes.