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Microsoft Security Bulletin MS11-041 - Critical
Vulnerability in Windows Kernel-Mode Drivers Could Allow Remote Code Execution (2525694)
Published: June 14, 2011

Version: 1.0
General Information
Executive Summary

This security update resolves a privately reported vulnerability in Microsoft Windows. The vulnerability could allow remote code execution if a user visits a network share (or visits a web site that points to a network share) containing a specially crafted OpenType font (OTF). In all cases, however, an attacker would have no way to force a user to visit such a web site or network share. Instead, an attacker would have to convince a user to visit the web site or network share, typically by getting them to click a link in an e-mail message or Instant Messenger message.

This security update is rated Critical for all supported editions, except for 32-bit editions, of Windows Vista, Windows Server 2008, Windows 7, and Windows Server 2008 R2; and Important for all supported editions, except for 32-bit editions, of Windows XP and Windows Server 2003. For more information, see the subsection, Affected and Non-Affected Software, in this section.

The security update addresses the vulnerability by correcting the way that the Windows kernel-mode driver validates pointers while parsing OpenType fonts. 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. The majority of customers have automatic updating enabled and will not need to take any action because this security update will be downloaded and installed automatically. Customers who have not enabled automatic updating need to check for updates and install this update manually. For information about specific configuration options in automatic updating, see Microsoft Knowledge Base Article 294871.

For administrators and enterprise installations, or end users who want to install this security update manually, Microsoft recommends that customers apply the update immediately using update management software, or by checking for updates using the Microsoft Update service.

See also the section, Detection and Deployment Tools and Guidance, later in this bulletin.

Known Issues. None
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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 
Operating System	Maximum Security Impact	Aggregate Severity Rating	Bulletins Replaced by this Update

Windows XP Professional x64 Edition Service Pack 2
	

Elevation of Privilege
	

Important
	

MS11-034

Windows Server 2003 x64 Edition Service Pack 2
	

Elevation of Privilege
	

Important
	

MS11-034

Windows Server 2003 with SP2 for Itanium-based Systems
	

Elevation of Privilege
	

Important
	

MS11-034

Windows Vista x64 Edition Service Pack 1 and Windows Vista x64 Edition Service Pack 2
	

Remote Code Execution
	

Critical
	

MS11-034

Windows Server 2008 for x64-based Systems and Windows Server 2008 for x64-based Systems Service Pack 2*
	

Remote Code Execution
	

Critical
	

MS11-034

Windows Server 2008 for Itanium-based Systems and Windows Server 2008 for Itanium-based Systems Service Pack 2
	

Remote Code Execution
	

Critical
	

MS11-034

Windows 7 for x64-based Systems and Windows 7 for x64-based Systems Service Pack 1
	

Remote Code Execution
	

Critical
	

MS11-034

Windows Server 2008 R2 for x64-based Systems and Windows Server 2008 R2 for x64-based Systems Service Pack 1*
	

Remote Code Execution
	

Critical
	

MS11-034

Windows Server 2008 R2 for Itanium-based Systems and Windows Server 2008 R2 for Itanium-based Systems Service Pack 1
	

Remote Code Execution
	

Critical
	

MS11-034

*Server Core installation affected. This update applies, with the same severity rating, to supported editions of Windows Server 2008 or Windows Server 2008 R2 as indicated, whether or not installed using the Server Core installation option. For more information on this installation option, see the TechNet articles, Managing a Server Core Installation and Servicing a Server Core Installation. Note that the Server Core installation option does not apply to certain editions of Windows Server 2008 and Windows Server 2008 R2; see Compare Server Core Installation Options.

Non-Affected Software
Operating System

Windows XP Service Pack 3

Windows Server 2003 Service Pack 2

Windows Vista Service Pack 1 and Windows Vista Service Pack 2

Windows Server 2008 for 32-bit Systems and Windows Server 2008 for 32-bit Systems Service Pack 2

Windows 7 for 32-bit Systems and Windows 7 for 32-bit Systems Service Pack 1
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Frequently Asked Questions (FAQ) Related to This Security Update

Where are the file information details? 
Refer to the reference tables in the Security Update Deployment section for the location of the file information details.

I am using an older release of the software discussed in this security bulletin. What should I do? 
The affected software listed in this bulletin have been tested to determine which releases are affected. Other releases are past their support life cycle. For more information about the product lifecycle, visit the Microsoft Support Lifecycle web site.

It should be a priority for customers who have older releases of the software to migrate to supported releases to prevent potential exposure to vulnerabilities. To determine the support lifecycle for your software release, see Select a Product for Lifecycle Information. For more information about service packs for these software releases, see Lifecycle Supported Service Packs.

Customers who require custom support for older software must contact their Microsoft account team representative, their Technical Account Manager, or the appropriate Microsoft partner representative for custom support options. Customers without an Alliance, Premier, or Authorized Contract can contact their local Microsoft sales office. For contact information, visit the Microsoft Worldwide Information web site, select the country in the Contact Information list, and then click Go to see a list of telephone numbers. When you call, ask to speak with the local Premier Support sales manager. For more information, see the Microsoft Support Lifecycle Policy FAQ.
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Vulnerability Information
	
Severity Ratings and Vulnerability Identifiers

The following severity ratings assume the potential maximum impact of the vulnerability. For information regarding the likelihood, within 30 days of this security bulletin's release, of the exploitability of the vulnerability in relation to its severity rating and security impact, please see the Exploitability Index in the June bulletin summary. For more information, see Microsoft Exploitability Index.
Vulnerability Severity Rating and Maximum Security Impact by Affected Software
Affected Software	Win32k OTF Validation Vulnerability - CVE-2011-1873	Aggregate Severity Rating

Windows XP Professional x64 Edition Service Pack 2
	

Important 
Elevation of Privilege
	

Important

Windows Server 2003 x64 Edition Service Pack 2
	

Important 
Elevation of Privilege
	

Important

Windows Server 2003 with SP2 for Itanium-based Systems
	

Important 
Elevation of Privilege
	

Important

Windows Vista x64 Edition Service Pack 1 and Windows Vista x64 Edition Service Pack 2
	

Critical 
Remote Code Execution
	

Critical

Windows Server 2008 for x64-based Systems and Windows Server 2008 for x64-based Systems Service Pack 2*
	

Critical 
Remote Code Execution
	

Critical

Windows Server 2008 for Itanium-based Systems and Windows Server 2008 for Itanium-based Systems Service Pack 2
	

Critical 
Remote Code Execution
	

Critical

Windows 7 for x64-based Systems and Windows 7 for x64-based Systems Service Pack 1
	

Critical 
Remote Code Execution
	

Critical

Windows Server 2008 R2 for x64-based Systems and Windows Server 2008 R2 for x64-based Systems Service Pack 1*
	

Critical 
Remote Code Execution
	

Critical

Windows Server 2008 R2 for Itanium-based Systems and Windows Server 2008 R2 for Itanium-based Systems Service Pack 1
	

Critical 
Remote Code Execution
	

Critical

*Server Core installation affected. This update applies, with the same severity rating, to supported editions of Windows Server 2008 or Windows Server 2008 R2 as indicated, whether or not installed using the Server Core installation option. For more information on this installation option, see the TechNet articles, Managing a Server Core Installation and Servicing a Server Core Installation. Note that the Server Core installation option does not apply to certain editions of Windows Server 2008 and Windows Server 2008 R2; see Compare Server Core Installation Options.
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Win32k OTF Validation Vulnerability - CVE-2011-1873

A remote code execution vulnerability exists due to the way that the Windows kernel-mode driver improperly parses specially crafted OpenType fonts on x64-based and Itanium-based systems. An attacker who successfully exploited this vulnerability could run arbitrary code in kernel mode. An attacker could then install programs; view, change, or delete data; or create new accounts with full administrative rights.

To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2011-1873.
	
Mitigating Factors for Win32k OTF Validation Vulnerability - CVE-2011-1873

Mitigation refers to a setting, common configuration, or general best-practice, existing in a default state, that could reduce the severity of exploitation of a vulnerability. The following mitigating factors may be helpful in your situation:
â