Technical Information

Brief overview of the risk:
This security update resolves two privately reported vulnerabilities in Microsoft Windows. The more severe of these vulnerabilities could allow remote code execution if messages received by the Internet Authentication Service server are copied incorrectly into memory when handling PEAP authentication attempts. On Windows Server 2008, the Internet Authentication Service is replaced by Network Policy Server (NPS).
Detailed Information on the risk:

A remote code execution vulnerability exists in implementations of Protected Extensible Authentication Protocol (PEAP) on the Internet Authentication Service. The vulnerability is due to incorrect copying into memory of messages received by the server when handling PEAP authentication attempts. An attacker who successfully exploited this vulnerability could take complete control of an affected system.

Further information on this exploit is available at : MS09-071