Technical Information

Brief overview of the risk:
This security update resolves one publicly disclosed vulnerability and one privately reported vulnerability in Microsoft Exchange and Windows SMTP Service. The more severe of these vulnerabilities could allow denial of service if an attacker sent a specially crafted DNS response to a computer running the SMTP service.
Detailed Information on the risk:

A denial of service vulnerability exists in the way that the Microsoft Windows Simple Mail Transfer Protocol (SMTP) component handles specially crafted DNS Mail Exchanger (MX) resource records. An attempt to exploit the vulnerability would not require authentication, allowing an attacker to exploit the vulnerability by sending a specially crafted network message to a computer running the SMTP service. An attacker who successfully exploited this vulnerability could cause the SMTP service to stop responding until restarted.

Further information on this exploit is available at : MS10-024