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Microsoft Security Bulletin MS09-033 - Important

Vulnerability in Virtual PC and Virtual Server Could Allow Elevation of Privilege (969856)

Published: | Updated:

Version: 2.0

General Information

Executive Summary

This security update resolves a privately reported vulnerability in Microsoft Virtual PC and Microsoft Virtual Server. An attacker who successfully exploited this vulnerability could execute arbitrary code and take complete control of an affected guest operating system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

This security update is rated Important for all supported editions of Virtual PC 2004, Virtual PC 2007, and Virtual Server 2005. For more information, see the subsection, Affected and Non-Affected Software, in this section.

The security update addresses the vulnerability by enforcing validation of privilege levels when executing machine instructions. For more information about the vulnerability, see the Frequently Asked Questions (FAQ) subsection for the specific vulnerability entry under the next section, Vulnerability Information.

Recommendation. Microsoft recommends that customers apply the update at the earliest opportunity.

Known Issues. Microsoft Knowledge Base Article 969856 documents the currently known issues that customers may experience when installing this security update.

Affected and Non-Affected Software

The following software have been tested to determine which versions or editions are affected. Other versions or editions are either past their support life cycle or are not affected. To determine the support life cycle for your software version or edition, visit Microsoft Support Lifecycle.

Affected Software

SoftwareMaximum Security ImpactAggregate Severity RatingBulletins Replaced by this Update
Microsoft Virtual PC 2004 Service Pack 1
(KB969856)
Elevation of PrivilegeImportantNone
Microsoft Virtual PC 2007
(KB969856)
Elevation of PrivilegeImportantNone
Microsoft Virtual PC 2007 Service Pack 1
(KB969856)
Elevation of PrivilegeImportantNone
Microsoft Virtual PC 2007 x64 Edition
(KB969856)
Elevation of PrivilegeImportantNone
Microsoft Virtual PC 2007 x64 Edition Service Pack 1
(KB969856)
Elevation of PrivilegeImportant None 
Microsoft Virtual Server 2005
(KB969856)
Elevation of PrivilegeImportantNone
Microsoft Virtual Server 2005 R2 Service Pack 1
(KB969856)
Elevation of PrivilegeImportantNone
Microsoft Virtual Server 2005 R2 x64 Edition Service Pack 1
(KB969856)
Elevation of PrivilegeImportantNone

Non-Affected Software

Software
Microsoft Virtual PC for Mac 7.1

Frequently Asked Questions (FAQ) Related to This Security Update

Vulnerability Information

Severity Ratings and Vulnerability Identifiers

Virtual PC and Virtual Server Privileged Instruction Decoding Vulnerability - CVE-2009-1542

Update Information

Detection and Deployment Tools and Guidance

Security Update Deployment

Other Information

Acknowledgments

Microsoft thanks the following for working with us to help protect customers:

  • Julien Tinnes and Tavis Ormandy of Google Inc. for reporting the Virtual PC and Virtual Server Privileged Instruction Decoding Vulnerability (CVE-2009-1542)

Microsoft Active Protections Program (MAPP)

To improve security protections for customers, Microsoft provides vulnerability information to major security software providers in advance of each monthly security update release. Security software providers can then use this vulnerability information to provide updated protections to customers via their security software or devices, such as antivirus, network-based intrusion detection systems, or host-based intrusion prevention systems. To determine whether active protections are available from security software providers, please visit the active protections Web sites provided by program partners, listed in Microsoft Active Protections Program (MAPP) Partners.

Support

  • Customers in the U.S. and Canada can receive technical support from Security Support or 1-866-PCSAFETY. There is no charge for support calls that are associated with security updates. For more information about available support options, see Microsoft Help and Support.
  • International customers can receive support from their local Microsoft subsidiaries. There is no charge for support that is associated with security updates. For more information about how to contact Microsoft for support issues, visit the International Support Web site.

Disclaimer

The information provided in the Microsoft Knowledge Base is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

Revisions

  • V1.0 (July 14, 2009): Bulletin published.
  • V1.1 (July 15, 2009): Added command line instructions for Windows Vista and Windows Server 2008. Also removed erroneous entry of update log file.
  • V2.0 (March 9, 2010): Rereleased this bulletin to add Microsoft Virtual Server 2005 to affected software. No other update packages are affected by this rerelease.