Technical Information

Brief overview of the risk:
This security update resolves two privately reported vulnerabilities in Windows DNS server. The more severe of these vulnerabilities could allow remote code execution if an attacker registers a domain, creates an NAPTR DNS resource record, and then sends a specially crafted NAPTR query to the target DNS server. Servers that do not have the DNS role enabled are not at risk.
Detailed Information on the risk:

A remote code execution vulnerability exists in the way that the Windows DNS Server improperly handles a specially crafted NAPTR query string in memory. An attacker who successfully exploited this vulnerability could run arbitrary code in the context of the system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

Further information on this exploit is available at : MS11-058