A recently detected flaw in the Microsoft DNS (Domain Name Services) Server’s RPC (Remote Procedure Call) management server might allow a remote attacker to execute arbitrary code.
The folks at MSRC updated their data and indicated that when a Windows DNS server is not properly protected (firewalling, ip-filtering) it can be exploited by sending malicious packets to the RPC ports (tcp/135, tcp/445, tcp/>1024).
The Metasploit framework already has a plugin to test vulnerable servers.
There’s a bulletin from US-CERT at http://www.us-cert.gov/cas/techalerts/TA07-103A.html.