Hello,

We are aware of a publicly disclosed vulnerability affecting Windows XP and Windows Server 2003. We are not aware of any current exploitation of this issue and customers running Windows Vista, Windows 7, Windows Server 2008, and Windows Server 2008 R2, are not vulnerable to this issue, or at risk of attack.

This issue was reported to us on June 5th, 2010 by a Google security researcher and then made public less than four days later, on June 9th, 2010.  Public disclosure of the details of this vulnerability and how to exploit it, without giving us time to resolve the issue for our potentially affected customers, makes broad attacks more likely and puts customers at risk

One of the main reasons we and many others across the industry advocate for responsible disclosure is that the software vendor who wrote the code is in the best position to fully understand the root cause. While this was a good find by the Google researcher, it turns out that the analysis is incomplete and the actual workaround Google suggested is easily circumvented. In some cases, more time is required for a comprehensive update that cannot be bypassed, and does not cause quality problems. 

We recognize that researchers across the entire industry are a vital part of identifying issues and continually improving security, and we continue to ask researchers to work with us through responsible disclosure to help minimize the risk to customers while improving security.

We have initiated our emergency response process and will continue to monitor the threat landscape for any signs of attack against this issue. Our Microsoft Active Protections Program (MAPP) partners have detailed information about this vulnerability and are developing protections where possible.

Update: customers can follow guidance in Security Advisory 2219475 to protect against this issue.

Update 6/25/2010:
The security researcher who disclosed this vulnerability has expressed concerns regarding the inclusion of his employer’s name in relation to this vulnerability.  While there continues to be a difference of opinion, we have included both this researcher’s view and our view in this blog post. His point of view is that he reported the vulnerability not as an employee, but as an individual action by him as an independent researcher.

At Microsoft we do not believe that its feasible to disassociate the two.  We believe the actions of employees, when related to the work they are doing at a technology company, should reflect the policies of their employer. 

Despite these differences of opinion, we continue an open dialog with this researcher and ask the security researcher community to continue working with us to help protect customers.

Mike Reavey
Director, MSRC