Microsoft Security Bulletin MS07-068 - Critical Vulnerability in Windows Media File Format Could Allow Remote Code Execution (941569 and 944275)

Microsoft Security Bulletin MS07-068 - Critical
Vulnerability in Windows Media File Format Could Allow Remote Code Execution (941569 and 944275)
Published: December 11, 2007

Version: 1.0
General Information
Executive Summary

This critical security update resolves a privately reported vulnerability in Windows Media File Format. This vulnerability could allow remote code execution if a user viewed a specially crafted file in Windows Media Format Runtime. 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.

This is a critical security update for supported editions of Windows Media Format Runtime 7.1, 9, 9.5, 11 and for Windows Media Services 9.1. For more information, see the subsection, Affected and Non-Affected Software, in this section.

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 immediately.

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 Component Maximum Security Impact Aggregate Severity Rating Bulletins Replaced by This Update
Windows Media Format Runtime 7.1

Microsoft Windows 2000 Service Pack 4

Windows Media Format Runtime 7.1 (KB941569)

Remote Code Execution

Critical

MS06-078
Windows Media Format Runtime 9

Windows 2000 Service Pack 4

Windows Media Format Runtime 9 (KB941569)

Remote Code Execution

Critical

MS06-078

Windows XP Service Pack 2

Windows Media Format Runtime 9 (KB941569)

Remote Code Execution

Critical

MS06-078
Windows Media Format Runtime 9.5

Windows XP Service Pack 2

Windows Media Format Runtime 9.5 (KB941569)

Remote Code Execution

Critical

See FAQ Related to This Security Update

Windows XP Professional x64 Edition and Windows XP Professional x64 Edition Service Pack 2

Windows Media Format Runtime 9.5 (KB941569)

Remote Code Execution

Critical

None

Windows Server 2003 Service Pack 1 and Windows Server 2003 Service Pack 2

Windows Media Format Runtime 9.5 (KB941569)

Remote Code Execution

Critical

None

Windows Server 2003 x64 Edition and Windows Server 2003 x64 Edition Service Pack 2

Windows Media Format Runtime 9.5 (KB941569)

Remote Code Execution

Critical

None
Windows Media Format Runtime 9.5 x64 Edition

Windows XP Professional x64 Edition and Windows XP Professional x64 Edition Service Pack 2

Windows Media Format Runtime 9.5 x64 Edition (KB941569)

Remote Code Execution

Critical

None

Windows Server 2003 x64 Edition and Windows Server 2003 x64 Edition Service Pack 2

Windows Media Format Runtime 9.5 x64 Edition (KB941569)

Remote Code Execution

Critical

None
Windows Media Format Runtime 11

Windows XP Service Pack 2

Windows Media Format Runtime 11 (KB941569)

Remote Code Execution

Critical

See FAQ Related to This Security Update

Windows XP Professional x64 Edition and Windows XP Professional x64 Edition Service Pack 2

Windows Media Format Runtime 11 (KB941569)

Remote Code Execution

Critical

None

Windows Vista

Windows Media Format Runtime 11 (KB941569)

Remote Code Execution

Critical

None

Windows Vista x64 Edition

Windows Media Format Runtime 11 (KB941569)

Remote Code Execution

Critical

None
Windows Media Services 9.1

Windows Server 2003 Service Pack 1 and Windows Server 2003 Service Pack 2

Windows Media Services 9.1 (KB944275)

Remote Code Execution

Critical

None

Windows Server 2003 x64 Edition and Windows Server 2003 x64 Edition Service Pack 2

Windows Media Services 9.1 x64 Edition (KB944275)

Remote Code Execution

Critical

None

Non-Affected Software
Software

Windows Media Player 6.4 when installed on Microsoft Windows 2000

Windows Media Player 6.4 when installed on Windows XP

Windows Media Player 6.4 when installed on Windows Server 2003

Windows Media Services 4.1 when installed on Microsoft Windows 2000

Microsoft Windows 2003 For Itanium-Based Systems and Windows Server 2003 with SP1 for Itanium-based Systems
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Frequently Asked Questions (FAQ) Related to This Security Update

What are the known issues that customers may experience when they install this security update?
Microsoft Knowledge Base Article 941569 and Microsoft Knowledge Base Article 944275 document the currently known issues that customers may experience when they install this security update. The articles also document recommended solutions for these issues.

On Windows XP Service Pack 2, does this bulletin replace all updates offered by MS06-078?
For Windows Media Format Runtime 9.5 and Windows Media Format Runtime 11 on Windows XP Service Pack 2, the update offered by Microsoft Knowledge Base Article 941569 will not supersede MS06-078. For Windows Media Format Runtime 9 on Windows XP Service Pack 2, the update offered by Microsoft Knowledge Base Article 941569 will supersede MS06-078. Customers using Windows Server Update Services (WSUS) will see two update bundles which have identical titles and descriptions for Windows XP Service Pack 2. This issue results from separation of detection metadata to detect different versions of Windows Media Format Runtime on Windows XP Service Pack 2. The solution is to deploy both update bundles for Windows XP Service Pack 2. For customers installing this update through Windows Update the Microsoft detections and deployment tools will install the correct updates so all files are replaced as superseded.

Why is Windows Server 2003 for Itanium-based Systems not listed in the affected or non-affected software sections?
Windows Media Format Runtime is not an installable component on Windows Server 2003 with SP1 for Itanium-based Systems and Windows Server 2003 with SP2 for Itanium-based Systems. Windows Media Services did not ship as an optional component on Windows Server 2003 with SP1 for Itanium-based Systems and Windows Server 2003 with SP2 for Itanium-based Systems.

I am using an older release of the software discussed in this security bulletin. What should I do?
This software has been tested to determine which releases are affected. Other releases are past their support life cycle. To determine the support life cycle for your software release, visit Microsoft Support Lifecycle.

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. For more information about the Windows Product Lifecycle, visit the following Microsoft Support Lifecycle. For more information about the extended security update support period for these software releases, visit the Microsoft Product Support Services Web site.

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, 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 Windows Operating System Product Support Lifecycle FAQ.

I’ve installed the Window Media Format (KB941569) security update, what version of wmasf.dll should I have installed?
Microsoft has provided detection and deployment guidance for these security updates. When you install this security update, the installer checks whether one or more of the files that are being updated on your system have previously been updated. To manually verify what file version of wmasf.dll should have been installed please refer to the following tables.

For Windows Media Format Runtime 7.1 on Microsoft Windows 2000 Service Pack 4:
File Name Version Date Time Size

wmasf.dll

7.10.0.3081

31-Oct-2007

10:17

245,760

wmvcore.dll

7.10.0.3081

31-Oct-2007

10:18

1,134,592

For Windows Media Format Runtime 9 on Microsoft Windows 2000 Service Pack 4, you may have either version 9.0.0.3355 or 9.0.0.3267 depending on your configuration:
File Name Version Date Time Size

wmasf.dll

9.0.0.3355

31-Oct-2007

10:17

222,720

wmvcore.dll

9.0.0.3355

31-Oct-2007

10:17

2,064,384

wmasf.dll

9.0.0.3267

31-Oct-2007

10:17

230,912

wmvcore.dll

9.0.0.3267

31-Oct-2007

10:17

2,109,440

Windows Media Format Runtime 9 when installed on all supported 32-bit editions of Windows XP:
File Name Version Date Time Size Folder

wmasf.dll

9.0.0.3355

28-Oct-2007

24:38

222,720

SP1GDR

wmvcore.dll

9.0.0.3355

28-Oct-2007

24:39

2,064,384

SP1QFE

wmasf.dll

9.0.0.3267

28-Oct-2007

24:39

230,912

SP1GDR

wmvcore.dll

9.0.0.3267

28-Oct-2007

24:37

2,109,440

SP1QFE

Windows Media Format Runtime 9.5 when installed on all supported 32-bit editions of Windows XP:
File Name Version Date Time Size Folder

wmasf.dll

10.0.0.4359

28-Oct-2007

24:39

228,864

SP1GDR

wmasf.dll

10.0.0.4060

28-Oct-2007

24:40

227,328

SP1QFE

For Windows Media Format Runtime 9.5 when installed on all supported 32-bit editions of Windows Server 2003:
File Name Version Date Time Size Folder

wmasf.dll

10.0.0.3710

23-Oct-2007

21:58

226, 816

SP1GDR

wmasf.dll

10.0.0.3710

23-Oct-2007

22:16

226,816

SP1QFE

wmasf.dll

10.0.0.4000

23-Oct-2007

22:32

228,864

SP2GDR

wmasf.dll

10.0.0.4000

23-Oct-2007

22:53

228,864

SP2QFE

For Windows Media Format Runtime 9.5 when installed on all supported x64-based editions of Windows Server 2003:
File Name Version Date Time Size CPU Folder

wwmasf.dll

10.0.0.3710

24-Oct-2007

13:07

226,816

x86

SP1GDR\WOW

wwmasf.dll

10.0.0.3710

24-Oct-2007

13:07

226,816

x86

SP1QFE\WOW

wwmasf.dll

10.0.0.4000

24-Oct-2007

13:17

228,864

x86

SP2GDR\WOW

wwmasf.dll

10.0.0.4000

24-Oct-2007

13:05

228,864

x86

SP2QFE\WOW

Windows Media Format Runtime 11 when installed on all supported 32-bit editions of Windows XP:
File Name Version Date Time Size

wmasf.dll

11.0.5721.5238

28-Oct-2007

24:40

222,720

Windows Media Format Runtime 11 when installed on all supported x64-based editions of Windows XP:
File Name Version Date Time Size CPU Folder

wmasf.dll

11.0.5721.5238

29-Oct-2007

10:31

222,720

x86

SP1QFE\WOW

For Windows Media Format Runtime 11 on all supported 32-bit editions of Windows Vista:
File Name Version Date Time Size Folder

wmasf.dll

11.0.6000.6345

25-Oct-2007

03:15

223,232

Windows6.0-KB941569-x86\x86_microsoft-windows-mediaplayer-wmasf_31bf3856ad364e35_6.0.6000.16585_none_a57e3226437ddd6f

wmasf.dll

11.0.6000.6345

25-Oct-2007

03:15

223,232

Windows6.0-KB941569-x86\x86_microsoft-windows-mediaplayer-wmasf_31bf3856ad364e35_6.0.6000.20708_none_a66151155c57e6dd

For Windows Media Format Runtime 11 on all supported x64-based editions of Windows Vista:
File Name Version Date Time Size CPU Folder

wmasf.dll

11.0.6000.6345

25-Oct-2007

24:18

301,056

x64

Windows6.0-KB941569-x64\amd64_microsoft-windows-mediaplayer-wmasf_31bf3856ad364e35_6.0.6000.16585_none_019ccda9fbdb4ea5

wmasf.dll

11.0.6000.6345

25-Oct-2007

04:05

301,056

x64

Windows6.0-KB941569-x64\amd64_microsoft-windows-mediaplayer-wmasf_31bf3856ad364e35_6.0.6000.20708_none_027fec9914b55813

wmasf.dll

11.0.6000.6345

25-Oct-2007

03:15

223,232

x86

Windows6.0-KB941569-x64\x86_microsoft-windows-mediaplayer-wmasf_31bf3856ad364e35_6.0.6000.16585_none_a57e3226437ddd6f

wmasf.dll

11.0.6000.6345

25-Oct-2007

03:15

223,232

x86

Windows6.0-KB941569-x64\x86_microsoft-windows-mediaplayer-wmasf_31bf3856ad364e35_6.0.6000

I’ve installed the Windows Media Services 9.1(KB944275) security update, what version of wmsserver.dll should I have installed?
Microsoft has provided detection and deployment guidance for these security updates. When you install this security update, the installer checks whether one or more of the files that are being updated on your system have previously been updated. To manually verify what file version of wmsserver.dll should have been installed please refer to the following tables.

Note Windows Media Services 9.1, which includes wmsserver.dll, is an optional operating system component on all supported 32-bit editions of Windows Server 2003, and x64-based editions of Windows Server 2003.

Note Windows Media Services 9.1, which includes wmsserver.dll, is not installable on any supported edition of Windows XP.

For Windows Media Services 9.1 when installed on all supported 32-bit editions of Windows Server 2003:
File Name Version Date Time Size Folder

wmsserver.dll

9.1.1.3844

13-Nov-2007

05:16

3,098,624

SP1GDR

wmsserver.dll

9.1.1.3844

13-Nov-2007

04:59

3,167,232

SP1QFE

wmsserver.dll

9.1.1.3862

13-Nov-2007

05:04

3,167,744

SP2GDR

wmsserver.dll

9.1.1.3862

13-Nov-2007

05:13

3,167,744

SP2QFE

For Windows Media Services 9.1 when installed all supported x64-based editions of Windows Server 2003:
File Name Version Date Time Size CPU Folder

wmsserver.dll

9.1.1.3844

13-Nov-2007

19:21

5,814,272

x86

SP1GDR

wmsserver.dll

9.1.1.3844

13-Nov-2007

19:21

5,821,952

x86

SP1QFE

wmsserver.dll

9.1.1.3862

13-Nov-2007

19:27

5,821,952

x86

SP2GDR

wmsserver.dll

9.1.1.3862

13-Nov-2007

19:20

5,821,952

x86

SP2QFE
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Vulnerability Information

Severity Ratings and Vulnerability Identifiers
Affected Software Windows Media Format Remote Code Execution Vulnerability Parsing ASF - CVE-2007-0064 Aggregate Severity Rating

Windows Media Format Runtime 7.1

Critical

Remote Code Execution

Critical

Windows Media Format Runtime 9

Critical

Remote Code Execution

Critical

Windows Media Format Runtime 9.5

Critical

Remote Code Execution

Critical

Windows Media Format Runtime 11

Critical

Remote Code Execution

Critical

Windows Media Format Runtime 9.5 x64 Edition

Critical

Remote Code Execution

Critical

Windows Media Services 9.1

Critical

Remote Code Execution

Critical
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Windows Media Format Remote Code Execution Vulnerability Parsing ASF - CVE-2007-0064

A remote code execution vulnerability exists in Windows Media Format Runtime due to the way it handles Advanced Systems Format (ASF) files. In client applications, such as Windows Media Player, an attacker could exploit the vulnerability by constructing specially crafted Windows Media Format Runtime content that could potentially allow remote code execution if a user visits a specially crafted Web site or opens an e-mail message with specially crafted content. In server applications, such as Windows Media Services, an attacker could exploit the vulnerability by constructing specially crafted Windows Media Format Runtime content that could potentially allow remote code execution if the server processes the specially crafted content. In client and server applications, an attacker who successfully exploited this vulnerability could take complete control of an affected system.

To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2007-0064.

Mitigating Factors for Windows Media Format Remote Code Execution Vulnerability Parsing ASF – CVE-2007-0064

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

Mitigating Factors for Client Application:
•

In a Web-based attack scenario, an attacker could host a Web site that contains a Web page that is used to exploit this vulnerability. In addition, compromised Web sites and Web sites that accept or host user-provided content or advertisements could contain specially crafted content that could exploit this vulnerability. In all cases, however, an attacker would have no way to force users to visit these Web sites. Instead, an attacker would have to convince users to visit the Web site, typically by getting them to click a link in an e-mail message or Instant Messenger message that takes users to the attacker's Web site.
•

An attacker who successfully exploited this vulnerability could gain the same user rights as the local user. Users whose accounts are configured to have fewer user rights on the system could be less affected than users who operate with administrative user rights.
•

Windows Media Player 6.4 when installed on Windows 2000, Windows XP, or Windows Server 2003 is not affected.
•

Mitigating Factors for Server Application:
•

An attacker who successfully exploited this vulnerability could gain the same privileges as the network service account.
•

Windows Media Services 9.1, which includes wmsserver.dll, is an optional operating system component on all supported 32-bit editions of Windows Server 2003, and x64-based editions of Windows Server 2003.
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Workarounds for Windows Media Format Remote Code Execution Vulnerability Parsing ASF – CVE-2007-0064

Workaround refers to a setting or configuration change that does not correct the underlying vulnerability but would help block known attack vectors before you apply the update. Microsoft has tested the following workarounds and states in the discussion whether a workaround reduces functionality:

The core workaround for these vulnerabilities is to deny access to the vulnerable DLLs on each affected operating system.
•

For client applications deny access to WMASF.DLL

From an administrative command prompt in Windows XP and Windows Server 2003 run the following command:

Echo y| cacls exe %WINDIR%\SYSTEM32\WMASF.DLL /E /P everyone:N

From an elevated command prompt in Windows Vista run the following commands:

Takeown.exe /f %WINDIR%\SYSTEM32\WMASF.DLL
Icacls.exe %WINDIR%\SYSTEM32\WMASF.DLL /save %TEMP%\WMASF_ACL.TXT
Icacls.exe %WINDIR%\SYSTEM32\WMASF.DLL /deny everyone:(F)

Impact of Workaround: Users will be unable to play Advanced Systems Format (ASF) files.
•

For server applications, Microsoft has not identified any workarounds for this vulnerability.
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FAQ for Windows Media Format Remote Code Execution Vulnerability Parsing ASF - CVE-2007-0064

What is the scope of the vulnerability?
A remote code execution vulnerability exists in Windows Media Format Runtime due to the way it handles Advanced Systems Format (ASF) files. In client applications, such as Windows Media Player, an attacker could exploit the vulnerability by constructing specially crafted Windows Media Format Runtime content that could potentially allow remote code execution if a user visits a specially crafted Web site or opens an e-mail message with specially crafted content. In server applications, such as Windows Media Services, an attacker could exploit the vulnerability by constructing specially crafted Windows Media Format Runtime content that could potentially allow remote code execution if the server processes the specially crafted content. In client and server applications, an attacker who successfully exploited this vulnerability could take complete control of an affected system.

What causes the vulnerability?
Incorrect parsing of Advanced Systems Format (ASF) files within the Windows Media Format Runtime.

What is Windows Media Format Runtime?
The Microsoft Windows Media Format Runtime provides information and tools for applications that use Windows Media content. For more information, see the product documentation.

What is Windows Media Services 9.1?
The Windows Media Services 9.1, which includes wmsserver.dll, is an optional operating system component on all supported 32-bit editions of Windows Server 2003, and x64-based editions of Windows Server 2003. This server application runs as a low privileged networking service account for processing media files. For more information, see the product documentation.

What is Advanced Systems Format (ASF)?
ASF (Advanced Systems Format) is a file format that stores audio and video information and is specially designed to run over networks like the Internet. It is a compressed format that contains streaming audio, video, slide shows, and synchronized events. ASF enables content to be delivered to you as a continuous flow of data. ASF files may have the file extensions ASF, WMV, or WMA.

What might an attacker use the vulnerability to do?
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 are less impacted than users who operate with administrative user rights.

How could an attacker exploit the vulnerability?
In a client Web-based attack scenario, an attacker could host a Web site designed to exploit this vulnerability through Windows Media Player. In no case, however, would an attacker have a way to force users to visit these Web sites. Instead, an attacker would have to convince users to visit the Web site, typically by getting them to click a link in an e-mail message or in an Instant Messenger request that takes users to the attacker's Web site. In server applications an attacker could exploit the vulnerability by constructing specially crafted Windows Media Format Runtime content that could potentially allow remote code execution if the server processes the specially crafted content.

What systems are primarily at risk from the vulnerability?
This vulnerability requires that a user is logged on and opens the specially crafted ASF file in any Windows Media Format Runtime-based application for any malicious action to occur. Therefore, any systems where Windows Media Format Runtime or Windows Media Server 9.1 s used frequently, such as workstations or terminal servers, are at the most risk from this vulnerability.

What does the update do?
The update removes the vulnerability by modifying the way that Windows Media Format Runtime parses Advanced Systems Format (ASF) files.

When this security bulletin was issued, had this vulnerability been publicly disclosed?
No. Microsoft received information about this vulnerability through responsible disclosure. Microsoft had not received any information to indicate that this vulnerability had been publicly disclosed when this security bulletin was originally issued.

When this security bulletin was issued, had Microsoft received any reports that this vulnerability was being exploited?
No. Microsoft had not received any information to indicate that this vulnerability had been publicly used to attack customers and had not seen any examples of proof of concept code published when this security bulletin was originally issued.

Other Information
Acknowledgments

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

Ryan Smith, IBM Internet Security Systems X-Force Researcher, of ISS X-Force for reporting the Windows Media Format Code Execution Vulnerability – (CVE-2007-0064).
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Support
•

Customers in the U.S. and Canada can receive technical support from Microsoft Product Support Services at 1-866-PCSAFETY. There is no charge for support calls that are associated with security updates.
•

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.
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Revisions
•

V1.0 (December 11, 2007): Bulletin published.