Severity Rating: Critical - Revision Note: V1.1 (April 22, 2009): Added Microsoft Windows 2000 Service Pack 4 with DirectX 7.0 to the Non-Affected Software table. This is an informational change only.Summary: This security update resolves a privately reported vulnerability in Microsoft DirectX. The vulnerability could allow remote code execution if user opened a specially crafted MJPEG file. 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.

Read more at: http://www.microsoft.com/technet/security/bulletin/MS09-011.mspx?pubDate=2009-04-22