Microsoft ISA Server DNS - Denial Of Service (MS03-009)

Summary
A flaw exists in the ISA Server DNS intrusion detection application filter. An attacker could exploit the vulnerability by sending a specially formed request to an ISA Server computer that is publishing a DNS server, which could then result in a denial of service to the published DNS server.
Solution
see http://www.microsoft.com/technet/security/bulletin/ms03-009.mspx