Description: This security update resolves one publicly disclosed vulnerability and two privately reported vulnerabilities in Microsoft Windows HTTP Services (WinHTTP). The most severe vulnerability could allow remote code execution. An attacker who successfully exploited this vulnerability could take complete control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights. The security update addresses the vulnerabilities by changing the way that Windows HTTP Services handles errors and validates certificates, and by ensuring that Windows HTTP Services correctly use NTLM credential reflection protection mechanisms.
Update type: Critical
Release date: April 14, 2009
Applies to: All versions
Knowledge base: http://support.microsoft.com/kb/960803