Red Hat has shipped a new version of its dnsmasq caching software to plug source UDP port bug. This could have made DNS spoofing attacks (CVE-2008-1447) easier. Dnsmasq is lightweight ultra fast dns cache server forwarder and DHCP server. It is designed to provide DNS and, optionally, DHCP, to a small network.
Explains how to use Windows nslookup command to verify your own or ISP recursive DNS resolvers are free from DNS cache poisoning bug.
Dan Kaminsky discovered that properties inherent to the DNS protocol lead to practical DNS cache poisoning attacks. Among other things, successful attacks can lead to misdirected web traffic and email rerouting.
The BIND DNS implementation does not randomize the UDP source port when doing remote queries, and the query id alone does not provide adequate randomization.