Severity Rating: Important - Revision Note: Bulletin published.Summary: This security update resolves a privately reported vulnerability in the Secure Channel (SChannel) security package in Windows. The vulnerability could allow spoofing if an attacker gains access to the certificate used by the end user for authentication. Customers are only affected when the public key component of the certificate used for authentication has been obtained by the attacker through other means.

Read more at: http://www.microsoft.com/technet/security/bulletin/MS09-007.mspx?pubDate=2009-03-10