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Microsoft Security Bulletin MS13-057 - Critical

Vulnerability in Windows Media Format Runtime Could Allow Remote Code Execution (2847883)

Published: July 09, 2013 | Updated: August 27, 2013

Version: 3.0

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 opens a specially crafted media file. 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 impacted than users who operate with administrative user rights.

This security update is rated Critical for all supported releases of Windows, excluding Itanium-based editions of Windows servers. For more information, see the subsection, Affected and Non-Affected Software, in this section.

The security update addresses the vulnerability by modifying how Windows Media Player opens certain media files. 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. Most 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.

Knowledge Base Article

Knowledge Base Article 2847883
File informationYes
SHA1/SHA2 hashesYes
Known issuesYes

Affected and Non-Affected Software

The following software has 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, see Microsoft Support Lifecycle.

Affected Software 

Operating SystemComponentMaximum Security ImpactAggregate Severity RatingUpdates Replaced
Windows XP
Windows XP Service Pack 3 (Media Center Edition only) Windows Media Format Runtime 11 [1]
(wmvdecod.dll)
(2834904)
Remote Code ExecutionCriticalNone
Windows XP Service Pack 3 (Media Center Edition only) Windows Media Format Runtime 9.5
(wmvdmod.dll)
(2834905)
Remote Code ExecutionCriticalNone
Windows XP Service Pack 3 Windows Media Format Runtime 9
(wmvdmod.dll)
(2803821)
Remote Code ExecutionCriticalNone
Windows XP Service Pack 3 Windows Media Format Runtime 9.5 [ 2 ]
(wmvdmod.dll)
(2834902)
Remote Code ExecutionCriticalNone
Windows XP Service Pack 3 Windows Media Format Runtime 9.5 [ 3 ]
(wmvdmod.dll)
(2834903)
Remote Code ExecutionCriticalNone
Windows XP Service Pack 3 Windows Media Format Runtime 11
(wmvdecod.dll)
(2834904)
Remote Code ExecutionCriticalNone
Windows XP Service Pack 3 wmv9vcm.dll (codec)
(2845142)
Remote Code ExecutionCriticalNone
Windows XP Professional x64 Edition Service Pack 2 Windows Media Format Runtime 9.5
(wmvdmod.dll)
(2803821)
Remote Code ExecutionCriticalNone
Windows XP Professional x64 Edition Service Pack 2 Windows Media Format Runtime 9.5 x64
(wmvdmod.dll)
(2834902)
Remote Code ExecutionCriticalNone
Windows XP Professional x64 Edition Service Pack 2 Windows Media Format Runtime 11
(wmvdecod.dll)
(2834904)
Remote Code ExecutionCriticalNone
Windows XP Professional x64 Edition Service Pack 2 wmv9vcm.dll (codec)
(2845142)
Remote Code ExecutionCriticalNone
Windows Server 2003
Windows Server 2003 Service Pack 2 Windows Media Format Runtime 9.5
(wmvdmod.dll)
(2803821)
Remote Code ExecutionCriticalNone
Windows Server 2003 Service Pack 2 wmv9vcm.dll (codec)
(2845142)
Remote Code ExecutionCriticalNone
Windows Server 2003 x64 Edition Service Pack 2 Windows Media Format Runtime 9.5
(wmvdmod.dll)
(2803821)
Remote Code ExecutionCriticalNone
Windows Server 2003 x64 Edition Service Pack 2 Windows Media Format Runtime 9.5 x64
(wmvdmod.dll)
(2834902)
Remote Code ExecutionCriticalNone
Windows Server 2003 x64 Edition Service Pack 2 Windows Media Format Runtime 11
(wmvdmod.dll)
(2834904)
Remote Code ExecutionCriticalNone
Windows Server 2003 x64 Edition Service Pack 2 wmv9vcm.dll (codec)
(2845142)
Remote Code ExecutionCriticalNone
Windows Vista
Windows Vista Service Pack 2 Windows Media Player 11 [5]
(wmvdecod.dll)
(2803821)
Remote Code ExecutionCriticalNone
Windows Vista Service Pack 2 wmv9vcm.dll (codec)
(2845142)
Remote Code ExecutionCriticalNone
Windows Vista x64 Edition Service Pack 2 Windows Media Player 11
(wmvdecod.dll)
(2803821)
Remote Code ExecutionCriticalNone
Windows Vista x64 Edition Service Pack 2 wmv9vcm.dll (codec)
(2845142)
Remote Code ExecutionCriticalNone
Windows Server 2008
Windows Server 2008 for 32-bit Systems Service Pack 2 Windows Media Player 11 [4][5]
(wmvdecod.dll)
(2803821)
Remote Code ExecutionCriticalNone
Windows Server 2008 for 32-bit Systems Service Pack 2 wmv9vcm.dll (codec) [7 ]
(2845142)
Remote Code ExecutionCriticalNone
Windows Server 2008 for x64-based Systems Service Pack 2 Windows Media Player 11 [4]
(wmvdecod.dll)
(2803821)
Remote Code ExecutionCriticalNone
Windows Server 2008 for x64-based Systems Service Pack 2 wmv9vcm.dll (codec) [7 ]
(2845142)
Remote Code ExecutionCriticalNone
Windows 7
Windows 7 for 32-bit Systems Service Pack 1 Windows Media Player 12
(wmvdecod.dll)
(2803821)
Remote Code ExecutionCriticalNone
Windows 7 for x64-based Systems Service Pack 1 Windows Media Player 12
(wmvdecod.dll)
(2803821)
Remote Code ExecutionCriticalNone
Windows Server 2008 R2
Windows Server 2008 R2 for x64-based Systems Service Pack 1 Windows Media Player 12 [4]
(wmvdecod.dll)
(2803821)
Remote Code ExecutionCriticalNone
Windows 8
Windows 8 for 32-bit Systems Windows Media Player 12
(wmvdecod.dll)
(2803821)
Remote Code ExecutionCriticalNone
Windows 8 for 64-bit Systems Windows Media Player 12
(wmvdecod.dll)
(2803821)
Remote Code ExecutionCriticalNone
Windows Server 2012
Windows Server 2012 Windows Media Player 12 [4]
(wmvdecod.dll)
(2803821)
Remote Code ExecutionCriticalNone
Windows RT
Windows RTWindows Media Player 12
(wmvdecod.dll)[6]
(2803821)
Remote Code ExecutionCriticalNone

[ 1 ]This update is only offered to systems that have been upgraded to Windows Media Format Runtime 11 or Windows Media Player 11. See the Update FAQ for more information.
[2]This update is only offered to systems running Windows Media Format Runtime 9.5 NL. See the Update FAQ for more information.
[3]This update is only offered to systems running Windows Media Format Runtime 9.5 L. See the Update FAQ for more information.
[4]This update is only offered if the optional Desktop Experience feature is enabled. See the Update FAQ for more information.
[5]Installing the 2803821 update on Windows Vista Service Pack 2 or Windows Server 2008 Service Pack 2 downgrades the version of wmvdecod.dll from 11.0.6001.xxxx to 6.0.6002.yyyy. 
[6]Windows RT security updates are provided via Windows Update.
[7]This update is only offered if the optional Desktop Experience feature is enabled and the wmv9vcm.dll codec is present. See the Update FAQ for more information.

 

Non-Affected Software

Operating System
Windows Server 2003 with SP2 for Itanium-based Systems
Windows Server 2008 for Itanium-based Systems Service Pack 2
Windows Server 2008 R2 for Itanium-based Systems Service Pack 1
Server Core installation option
Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)
Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)
Windows Server 2012 (Server Core installation)

Why was this bulletin revised on August 27, 2013? 
Microsoft revised this bulletin to rerelease the following updates for the specified editions of Windows:

  • For Windows XP: The 2803821, 2834902, 2834903, 2834904, and 2834905 updates
  • For Windows Server 2003: The 2803821, 2834902, and 2834904 updates
  • For Windows Vista: The 2803821 update
  • For Windows Server 2008: The 2803821 update

The rereleased updates address an application compatibility issue in which WMV encoded video could fail to properly render during playback. Customers should install the rereleased updates.

Why was this bulletin revised on August 13, 2013? 
Microsoft revised this bulletin to rerelease the 2803821 update for Windows 7 and Windows Server 2008 R2. The rereleased update addresses an application compatibility issue in which WMV encoded video could fail to properly render during playback. Windows 7 and Windows Server 2008 R2 customers should install the rereleased update.

I alr eady have the original update s installed. D o I still need to apply the rereleased update s to be protected from the vulnerability described in this bulletin ?  
Customers who have already installed the original 2803821, 2834902, 2834903, 2834904, and 2834905 updates are protected from CVE-2013-3127. However, customers need to install the rereleased updates to avoid the playback issues that some customers are experiencing and that are addressed by the rerelease.

How are Server Core installations affected by the vulnerabilities addressed in this bulletin? 
The vulnerabilities addressed by this update do not affect supported editions of Windows Server 2008, Windows Server 2008 R2, or Windows Server 2012 as indicated in the Non-Affected Software table, when installed using the Server Core installation option. For more information on this installation option, see the TechNet articles, Managing a Server Core Installation: Overview, Servicing a Server Core Installation, and Server Core and Full Server Integration Overview.

There are two security update s listed in the Affected Software table for Windows XP Media Center Edition . Do I need to install both updates to be protected from the vulnerability described in this bulletin ? 
There are two security updates available for Windows XP Media Center Edition (2834904 and 2834905). Customers should install one or the other depending on whether or not their version of Media Player has been upgraded to version 11. Customers running Windows Media Format Runtime 9.5 on Windows XP Media Center Edition should apply the 2834905 update; however, customers who have upgraded to Windows Media Format Runtime 11 or Windows Media Player 11 should apply the 2834904 update. Customers will be offered the 2834904 only if their systems have been upgraded.

There are two security update s listed in the Affected Software table for Windows Media Format Runtime 9.5 on Windows XP Service Pack 3 . Do I need to install both updates to be protected from the vulnerability described in this bulletin ? 
There are two security updates available for Windows Media Format Runtime 9.5 on Windows XP Service Pack 3 (2834902 and 2834903). Customers should install one or the other depending on the version of the Windows Media Format Runtime binary installed on their system. Customers running Windows Media Format Runtime 9.5 NL should install the 2834902 update and customers running Windows Media Format Runtime 9.5 L should install the 2834903 update. Customers will be offered the correct update based on the binary present on their systems.

I am running Windows Server 2008, Windows Server 2008 R2, or Windows Server 2012, which are listed as affected software, why am I not being offered the updates?
Windows Media Player on Windows Server 2008, Windows Server 2008 R2, and Windows Server 2012 is installed as a part of the optional Desktop Experience feature. Therefore, if the Desktop Experience feature has not been installed or enabled on these systems, then the vulnerable components in Windows Media Player will not be present and the updates will not be offered. See Desktop Experience Overview for more information about this optional feature.

There are multiple security update s listed in the Affected Software table for Windows XP, Windows Server 2003, Windows Vista , and Windows Server 2008 . Do I need to install all of the updates for my operating system to be protected from the vulnerability described in this bulletin ? 
Yes, to be protected from the vulnerability described in this bulletin, customers should apply the update for their version of Windows Media Format Runtime or Windows Media Player, as well as any non-version-specific codec update listed for their operating system.

Do I need to install multiple security updates in a particular sequence? 
No. Multiple updates for a given operating system can be applied in any sequence.

How do I determine which version of Windows Media Player is installed on my system? 
For instructions on how to determine the version of Windows Media Player that is installed on a system, see Microsoft Knowledge Base Article 190990.

How do I determine which version of Windows Media Format Runtime is installed on my system? 
To determine the version of Windows Media Format Runtime that is installed on your system, navigate to the folder containing the.dll file listed in Affected Software for your operating system (e.g., wmvdmod.dll on Windows XP Service Pack 3). For 32-bit systems, the file is in the %SystemRoot%\System32 folder. For x64-based systems, the file is in the %SystemRoot%\syswow64 folder.

I installed the 2803821 update on Windows Vista Service Pack 2 or Windows Server 2008 Service Pack 2 and noticed the version of wmvdecod.dll was downgraded from 11.0.6001.xxxx to 6.0.6002.yyyy. Is this expected?  
Yes, this is the expected result after applying the wmvdecod.dll update on Windows Vista Service Pack 2 or Windows Server 2008 Service Pack 2.

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 has been tested to determine which releases are affected. Other releases are past their support life cycle. For more information about the product lifecycle, see the Microsoft Support Lifecycle website.

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 Service Pack Lifecycle Support Policy.

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, see the Microsoft Worldwide Information website, 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.

Vulnerability Information

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 July bulletin summary. For more information, see Microsoft Exploitability Index.

Vulnerability Severity Rating and Maximum Security Impact by Affected Software
Affected SoftwareWMV Video Decoder Remote Code Execution Vulnerability - CVE-2013-3127Aggregate Severity Rating
Windows XP
Windows Media Format Runtime 11 (wmvdecod.dll) on Windows XP Service Pack 3 (Media Center Edition only)
(2834904)
Critical 
Remote Code Execution
Critical
Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows XP Service Pack 3 (Media Center Edition only)
(2834905)
Critical 
Remote Code Execution
Critical
Windows Media Format Runtime 9 (wmvdmod.dll) on Windows XP Service Pack 3
(2803821)
Critical 
Remote Code Execution
Critical
Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows XP Service Pack 3
(2834902)
Critical 
Remote Code Execution
Critical
Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows XP Service Pack 3
(2834903)
Critical 
Remote Code Execution
Critical
Windows Media Format Runtime 11 (wmvdecod.dll) when installed on Windows XP Service Pack 3
(2834904)
Critical 
Remote Code Execution
Critical
wmv9vcm.dll (codec) on Windows XP Service Pack 3
(2845142)
Critical 
Remote Code Execution
Critical
Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows XP Professional x64 Edition Service Pack 2
(2803821)
Critical 
Remote Code Execution
Critical
Windows Media Format Runtime 9.5 x64 (wmvdmod.dll) on Windows XP Professional x64 Edition Service Pack 2
(2834902)
Critical 
Remote Code Execution
Critical
Windows Media Format Runtime 11 (wmvdecod.dll) when installed on Windows XP Professional x64 Edition Service Pack 2
(2834904)
Critical 
Remote Code Execution
Critical
wmv9vcm.dll (codec) on Windows XP Professional x64 Edition Service Pack 2
(2845142)
Critical 
Remote Code Execution
Critical
Windows Server 2003
Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows Server 2003 Service Pack 2
(2803821)
Critical 
Remote Code Execution
Critical
wmv9vcm.dll (codec) on Windows Server 2003 Service Pack 2
(2845142)
Critical 
Remote Code Execution
Critical
Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows Server 2003 x64 Edition Service Pack 2
(2803821)
Critical 
Remote Code Execution
Critical
Windows Media Format Runtime 9.5 x64 (wmvdmod.dll) on Windows Server 2003 x64 Edition Service Pack 2
(2834902)
Critical 
Remote Code Execution
Critical
Windows Media Format Runtime 11 (wmvdmod.dll) on Windows Server 2003 x64 Edition Service Pack 2
(2834904)
Critical 
Remote Code Execution
Critical
wmv9vcm.dll (codec) on Windows Server 2003 x64 Edition Service Pack 2
(2845142)
Critical 
Remote Code Execution
Critical
Windows Vista
Windows Media Player 11 (wmvdecod.dll) on Windows Vista Service Pack 2
(2803821)
Critical 
Remote Code Execution
Critical
wmv9vcm.dll (codec) on Windows Vista Service Pack 2
(2845142)
Critical 
Remote Code Execution
Critical
Windows Media Player 11 (wmvdecod.dll) on Windows Vista x64 Edition Service Pack 2
(2803821)
Critical 
Remote Code Execution
Critical
wmv9vcm.dll (codec) on Windows Vista x64 Edition Service Pack 2
(2845142)
Critical 
Remote Code Execution
Critical
Windows Server 2008
Windows Media Player 11 (wmvdecod.dll) on Windows Server 2008 for 32-bit Systems Service Pack 2
(2803821)
Critical 
Remote Code Execution
Critical
Windows Media Player 11 (wmvdecod.dll) on Windows Server 2008 for x64-based Systems Service Pack 2
(2803821)
Critical 
Remote Code Execution
Critical
wmv9vcm.dll (codec) on Windows Server 2008 for 32-bit Systems Service Pack 2
(2845142)
Critical 
Remote Code Execution
Critical
wmv9vcm.dll (codec) on Windows Server 2008 for x64-based Systems Service Pack 2
(2845142)
Critical 
Remote Code Execution
Critical
Windows 7
Windows Media Player 12 (wmvdecod.dll) on Windows 7 for 32-bit Systems Service Pack 1
(2803821)
Critical 
Remote Code Execution
Critical
Windows Media Player 12 (wmvdecod.dll) on Windows 7 for x64-based Systems Service Pack 1
(2803821)
Critical 
Remote Code Execution
Critical
Windows Server 2008 R2
Windows Media Player 12 (wmvdecod.dll) on Windows Server 2008 R2 for x64-based Systems Service Pack 1
(2803821)
Critical 
Remote Code Execution
Critical
Windows 8
Windows Media Player 12 (wmvdecod.dll) on Windows 8 for 32-bit Systems
(2803821)
Critical 
Remote Code Execution
Critical
Windows Media Player 12 (wmvdecod.dll) on Windows 8 for 64-bit Systems
(2803821)
Critical 
Remote Code Execution
Critical
Windows Server 2012
Windows Media Player 12 (wmvdecod.dll) on Windows Server 2012
(2803821)
Critical 
Remote Code Execution
Critical
Windows RT
Windows Media Player 12 (wmvdecod.dll) on Windows RT
(2803821)
Critical 
Remote Code Execution
Critical

A remote code execution vulnerability exists in the way Windows Media Format Runtime handles certain media files. This vulnerability could allow an attacker to execute arbitrary code if the attacker convinces a user to open a specially crafted media file. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2013-3127.

Mitigating Factors

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:

  • 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 impacted than users who operate with administrative user rights.
  • The vulnerability cannot be exploited automatically through email. For an attack to be successful a user would have to open a specially crafted media file that was sent as an attachment in an email message.
  • In a web-based attack scenario, an attacker could host a website that contains a webpage that is used to exploit this vulnerability. In addition, compromised websites and websites 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 websites. Instead, an attacker would have to convince users to visit the website, typically by getting them to click a link in an email message or Instant Messenger message that takes users to the attacker's website.
  • On Windows Server 2008, Windows Server 2008 R2, and Windows Server 2012 systems, the Desktop Experience feature, which is required for Windows Media Player and its vulnerable components to be present, is not enabled by default.

Workarounds

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:

  • Restrict access to the WMV codec using an interactive, managed script

    On Windows XP and Windows Server 2003 (32-bit systems) :

    Run the following command from an elevated command prompt:

    cacls %windir%\System32\Wmvdecod.dll /E /P everyone:N

    On Windows XP and Windows Server 2003 ( 64- bit systems):

    Run the following commands from an elevated command prompt:

    cacls %windir%\System32\Wmvdecod.dll /E /P everyone:N
    cacls %windir%\sysWOW64\Wmvdecod.dll /E /P everyone:N

    On Windows Vista and Windows Server 2008 (32-bit systems):

    Run the following commands from an elevated command prompt:

    takeown /f %windir%\System32\Wmvdecod.dll
    icacls %windir%\System32\Wmvdecod.dll /save %TEMP%\FILENAME_ACL.TXT
    icacls %windir%\System32\Wmvdecod.dll /deny everyone:(F)

    On Windows Vista and Windows Server 2008 ( 64-bit systems):

    Run the following commands from an elevated command prompt:

    takeown /f %windir%\System32\Wmvdecod.dll
    icacls %windir%\System32\Wmvdecod.dll /save %TEMP%\FILENAME_ACL.TXT
    icacls %windir%\System32\Wmvdecod.dll /deny everyone:(F)
    takeown /f %windir%\sysWOW64\Wmvdecod.dll
    icacls %windir%\SysWOW64\Wmvdecod.dll /save %TEMP%\FILENAME_ACL.TXT
    icacls %windir%\SysWOW64\Wmvdecod.dll /deny everyone:(F)

    Impact of workaround. After performing these steps, applications that use the WMV codec will not be able to play content.

  • Disable the WMV codec using an interactive, managed script

    Disabling the WMV codec will help protect the affected system from attempts to exploit this vulnerability.
    Note Roll-back not supported in Windows XP.

    Warning If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

    To disable the WMV codec, perform the following steps:

    1. Create a file named "Enable Workaround.reg" with the following contents:

      Windows Registry Editor Version 5.00

      [-HKEY_CLASSES_ROOT\CLSID\{82d353df-90bd-4382-8bc2-3f6192b76e34}]

      [-HKEY_CLASSES_ROOT\Wow6432Node\CLSID\{82d353df-90bd-4382-8bc2-3f6192b76e34}]

    2. Run the file as an administrator to disable the WMV codec.

    Impact of workaround. WMV-encoded files will not play.

    How to undo the workaround. 

    To undo the workaround:

    1. Create a file named "Disable Workaround.reg" with the following contents:

      Windows Registry Editor Version 5.00

      [HKEY_CLASSES_ROOT\CLSID\{82d353df-90bd-4382-8bc2-3f6192b76e34}]
      @="WMVideo Decoder DMO"
      "Merit"=dword:00800001
      "WMSDKMerit"=dword:00000100

      [HKEY_CLASSES_ROOT\CLSID\{82d353df-90bd-4382-8bc2-3f6192b76e34}\InprocServer32]
      @="C:\\Windows\\System32\\wmvdecod.dll"
      "ThreadingModel"="Both"

      [HKEY_CLASSES_ROOT\Wow6432Node\CLSID\{82d353df-90bd-4382-8bc2-3f6192b76e34}]
      @="WMVideo Decoder DMO"
      "Merit"=dword:00800001
      "WMSDKMerit"=dword:00000100

      [HKEY_CLASSES_ROOT\Wow6432Node\CLSID\{82d353df-90bd-4382-8bc2-3f6192b76e34}\InprocServer32]
      @="C:\\Windows\\SysWOW64\\wmvdecod.dll"
      "ThreadingModel"="Both"

    2. Run the file as an administrator to undo the workaround.

     

FAQ

What is the scope of the vulnerability? 
This is a remote code execution vulnerability. 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.

What causes the vulnerability? 
This vulnerability is caused when Windows Media Player fails to properly parse specially crafted media files.

What is Windows Media Player ? 
Windows Media Player is a feature of the Windows operating system for personal computers. It is used for playing audio and video.

How do I determine which version of Windows Media Player is installed on my system? 
For instructions on how to determine the version of Windows Media Player that is installed on a system, see Microsoft Knowledge Base Article 190990.

What might an attacker use the vulnerability to do? 
An attacker who successfully exploited this vulnerability could run arbitrary code as the logged-on user. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. If a user is logged-on with administrative user rights, an attacker could take complete control of the affected system. 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.

How could an attacker exploit the vulnerability? 
An attacker could exploit the vulnerability by hosting a specially crafted media file on a network location and convincing a user to open the file. An attacker would have no way to force users to open the file. Instead, an attacker would have to convince users to do so, typically by getting them to click a link in an email message or Instant Messenger message.

What systems are primarily at risk from the vulnerability? 
Systems, most typically workstations, that use Windows Media Player are primarily at risk from the vulnerability.

What does the update do? 
The update addresses the vulnerability by modifying how Windows Media Player opens certain media files.

When this security bulletin was issued, had this vulnerability been publicly disclosed? 
No. Microsoft received information about this vulnerability through coordinated vulnerability disclosure.

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 when this security bulletin was originally issued.

Update Information

Several resources are available to help administrators deploy security updates. 

  • Microsoft Baseline Security Analyzer (MBSA) lets administrators scan local and remote systems for missing security updates and common security misconfigurations. 
  • Windows Server Update Services (WSUS), Systems Management Server (SMS), and System Center Configuration Manager (SCCM) help administrators distribute security updates. 
  • The Update Compatibility Evaluator components included with Application Compatibility Toolkit aid in streamlining the testing and validation of Windows updates against installed applications. 

For information about these and other tools that are available, see Security Tools for IT Pros

Affected Software

For information about the specific security update for your affected software, click the appropriate link:

Windows XP (all editions)

Reference Table

The following table contains the security update information for this software.

Security update file names For Windows Media Format Runtime 11 (wmvdecod.dll) on Windows XP Service Pack 3 (Media Center Edition only):
WindowsXP-WindowsMedia-KB2834904-v2-x86-ENU.exe
 

Note This update is only for systems that have been upgraded to run Windows Media Format Runtime 11 or Windows Media Player 11.
For Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows XP Service Pack 3 (Media Center Edition only):
WindowsXP-WindowsMedia-KB2834905-v2-x86-ENU.exe
For Windows Media Format Runtime 9 (wmvdmod.dll) on Windows XP Service Pack 3:
WindowsXP-WindowsMedia-KB2803821-v2-x86-ENU.exe
For Windows Media Format Runtime 9.5 x64 (wmvdmod.dll) on Windows XP Service Pack 3:
WindowsXP-WindowsMedia-KB2834902-v2-x86-ENU.exe
For Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows XP Service Pack 3:
WindowsXP-WindowsMedia-KB2834903-v2-x86-ENU.exe
For Windows Media Format Runtime 11 (wmvdecod.dll) when installed on Windows XP Service Pack 3:
WindowsXP-WindowsMedia-KB2834904-v2-x86-ENU.exe
For wmv9vcm.dll (codec) on Windows XP Service Pack 3:
WindowsXP-WindowsMedia-KB2845142-x86-ENU.exe
For Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows XP Professional x64 Edition Service Pack 2:
WindowsServer2003.WindowsXP-KB2803821-v2-x64-ENU.exe
For Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows XP Professional x64 Edition Service Pack 2:
WindowsServer2003.WindowsXP-WindowsMedia-KB2834902-v2-x64-ENU.exe
For Windows Media Format Runtime 11 (wmvdecod.dll) when installed on Windows XP Professional x64 Edition Service Pack 2:
WindowsServer2003.WindowsXP-WindowsMedia-KB2834904-v2-x64-ENU.exe
For wmv9vcm.dll (codec) on Windows XP Professional x64 Edition Service Pack 2:
WindowsServer2003.WindowsXP-WindowsMedia-KB2845142-x64-ENU.exe
Installation switches See Microsoft Knowledge Base Article 262841
Update log file KB2803821-v2.log
KB2834902-v2.log
KB2834903-v2.log
KB2834904-v2.log
KB2834905-v2.log
KB2845142.log
Restart requirement In some cases, this update does not require a restart. If the required files are being used, this update will require a restart. If this behavior occurs, a message appears that advises you to restart.
Removal i nformation Use Add or Remove Programs item in Control Panel or the Spuninst.exe utility located in the following folders:
For Windows Media Format Runtime 9.5 (wmvdecod.dll) on Windows XP Service Pack 3 (Media Center Edition only):
%Windir%\$NTUninstallKB2834904-v2$\Spuninst
For Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows XP Service Pack 3 (Media Center Edition only):
%Windir%\$NTUninstallKB2834905-v2$\Spuninst
For Windows Media Format Runtime 9 (wmvdmod.dll) on Windows XP Service Pack 3:
%Windir%\$NTUninstallKB2803821-v2$\Spuninst
For Windows Media Format Runtime 9.5 x64 (wmvdmod.dll) on Windows XP Service Pack 3:
%Windir%\$NTUninstallKB2834902-v2$\Spuninst
For Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows XP Service Pack 3:
%Windir%\$NTUninstallKB2834903-v2$\Spuninst
For Windows Media Format Runtime 11 (wmvdecod.dll) when installed on Windows XP Service Pack 3:
%Windir%\$NTUninstallKB2834904-v2$\Spuninst
For wmv9vcm.dll (codec) on Windows XP Service Pack 3:
%Windir%\$NTUninstallKB2845142$\Spuninst
For Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows XP Professional x64 Edition Service Pack 2:
%Windir%\$NTUninstallKB2803821-v2$\Spuninst
For Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows XP Professional x64 Edition Service Pack 2:
%Windir%\$NTUninstallKB2834902-v2$\Spuninst
For Windows Media Format Runtime 11 (wmvdecod.dll) when installed on Windows XP Professional x64 Edition Service Pack 2:
%Windir%\$NTUninstallKB2834904-v2_WM11Lx64$\Spuninst
For wmv9vcm.dll (codec) on Windows XP Professional x64 Edition Service Pack 2:
%Windir%\$NTUninstallKB2845142$\Spuninst
File information See Microsoft Knowledge Base Article 2847883
Registry key verification For Windows Media Format Runtime 9.5 (wmvdecod.dll) on Windows XP Service Pack 3 (Media Center Edition only):
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows Media Player\KB2834904-v2_WM9
For Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows XP Service Pack 3 (Media Center Edition only):
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows Media Player\KB2834905-v2_WM9
For Windows Media Format Runtime 9 (wmvdmod.dll) on Windows XP Service Pack 3:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows Media Player\KB2803821-v2_WM9
For Windows Media Format Runtime 9.5 x64 (wmvdmod.dll) on Windows XP Service Pack 3:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows Media Player\KB2834902-v2_WM9
For Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows XP Service Pack 3:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows Media Player\KB2834903-v2_WM9
For Windows Media Format Runtime 11 (wmvdecod.dll) when installed on Windows XP Service Pack 3:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows Media Player\KB2834904-v2_WM11
For wmv9vcm.dll (codec) on Windows XP Service Pack 3:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows XP\SP4\KB2845142\Filelist
For Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows XP Professional x64 Edition Service Pack 2:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows XP Version 2003\SP3\KB2803821-v2
For Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows XP Professional x64 Edition Service Pack 2:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows XP Version 2003\SP3\KB2834902-v2
For Windows Media Format Runtime 11 (wmvdecod.dll) when installed on Windows XP Professional x64 Edition Service Pack 2:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows Media Format 11 SDK\KB2834904-v2_WM11x64
or wmv9vcm.dll (codec) on Windows XP Professional x64 Edition Service Pack 2:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows XP Version 2003\SP3\KB2845142

Windows Server 2003 (all editions)

Reference Table

The following table contains the security update information for this software.

Security update file names For Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows Server 2003 Service Pack 2:
WindowsServer2003-KB2803821-v2-x86-ENU.exe
For wmv9vcm.dll (codec) on Windows Server 2003 Service Pack 2:
WindowsServer2003-WindowsMedia-KB2845142-x86-ENU.exe
For Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows Server 2003 x64 Edition Service Pack 2:
WindowsServer2003.WindowsXP-KB2803821-v2-x64-ENU.exe
For Windows Media Format Runtime 9.5 x64 (wmvdmod.dll) on Windows Server 2003 x64 Edition Service Pack 2:
WindowsServer2003.WindowsXP-WindowsMedia-KB2834902-v2-x64-ENU.exe
For Windows Media Format Runtime 11 (wmvdmod.dll) on Windows Server 2003 x64 Edition Service Pack 2:
WindowsServer2003.WindowsXP-WindowsMedia-KB2834904-v2-x64-ENU.exe
For wmv9vcm.dll (codec) on Windows Server 2003 x64 Edition Service Pack 2:
WindowsServer2003.WindowsXP-WindowsMedia-KB2845142-x64-ENU.exe
Installation switches See Microsoft Knowledge Base Article 262841
Update log file KB2803821-v2.log
KB2845142.log
KB2834902-v2.log
KB2834904-v2.log
KB2845142.log
Restart requirement In some cases, this update does not require a restart. If the required files are being used, this update will require a restart. If this behavior occurs, a message appears that advises you to restart.
Removal information Use Add or Remove Programs item in Control Panel or the Spuninst.exe utility located in the following folders
For Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows Server 2003 Service Pack 2:
%Windir%\$NTUninstallKB2803821-v2$\Spuninst
For wmv9vcm.dll (codec) on Windows Server 2003 Service Pack 2:
%Windir%\$NTUninstallKB2845142$\Spuninst
For Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows Server 2003 x64 Edition Service Pack 2:
%Windir%\$NTUninstallKB2803821-v2$\Spuninst
For Windows Media Format Runtime 9.5 x64 (wmvdmod.dll) on Windows Server 2003 x64 Edition Service Pack 2:
%Windir%\$NTUninstallKB2834902-v2_WM10Lx64$\Spuninst
For Windows Media Format Runtime 11 (wmvdecod.dll) on Windows Server 2003 x64 Edition Service Pack 2:
%Windir%\$NTUninstallKB2834904-v2_WM11Lx64$\Spuninst
For wmv9vcm.dll (codec) on Windows Server 2003 x64 Edition Service Pack 2:
%Windir%\$NTUninstallKB2845142$\Spuninst
File information See Microsoft Knowledge Base Article 2847883
Registry key verification For Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows Server 2003 Service Pack 2:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows Server 2003\SP3\KB2803821-v2
For wmv9vcm.dll (codec) on Windows Server 2003 Service Pack 2:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows Server 2003\SP3\KB2845142
For Windows Media Format Runtime 9.5 (wmvdmod.dll) on Windows Server 2003 x64 Edition Service Pack 2:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows Server 2003\SP3\KB2803821-v2
For Windows Media Format Runtime 11 (wmvdecod.dll) on Windows Server 2003 x64 Edition Service Pack 2:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows Media Format 11 SDK\KB2834904-v2_WM11x64
For Windows Media Format Runtime 9.5 x64 (wmvdmod.dll) on Windows Server 2003 x64 Edition Service Pack 2:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows Media Format 9.5 SDK\KB2834902-v2_WM10Lx64
For wmv9vcm.dll (codec) on Windows Server 2003 x64 Edition Service Pack 2:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows Server 2003\SP3\KB2845142

Windows Vista (all editions)

Reference Table

The following table contains the security update information for this software.

Security update file names Windows Media Player 11 (wmvdecod.dll) on Windows Vista Service Pack 2:
Windows6.0-KB2803821-v2-x86.msu
wmv9vcm.dll (codec) on Windows Vista Service Pack 2:
Windows6.0-WindowsMedia-KB2845142-x86-ENU.exe
Windows Media Player 11 (wmvdecod.dll) on Windows Vista x64 Edition Service Pack 2:
Windows6.0-KB2803821-v2-x64.msu
wmv9vcm.dll (codec) on Windows Vista x64 Edition Service Pack 2:
Windows6.0-WindowsMedia-KB2845142-x64-ENU.exe
Installation switches See Microsoft Knowledge Base Article 934307
Restart requirement In some cases, this update does not require a restart. If the required files are being used, this update will require a restart. If this behavior occurs, a message appears that advises you to restart.
Removal information WUSA.exe does not support uninstall of updates. To uninstall an update installed by WUSA, click Control Panel, and then click Security. Under Windows Update, click View installed updates and select from the list of updates.
File information See Microsoft Knowledge Base Article 2847883
Registry key verification Note A registry key does not exist to validate the presence of this update.

Windows Server 2008 (all editions)

Reference Table

The following table contains the security update information for this software.

Security update file names Windows Media Player 11 (wmvdecod.dll) on Windows Server 2008 for 32-bit Systems Service Pack 2:
Windows6.0-KB2803821-v2-x86.msu
wmv9vcm.dll (codec) on Windows Server 2008 for 32-bit Systems Service Pack 2:
Windows6.0-WindowsMedia-KB2845142-x86-ENU.exe
Windows Media Player 11 (wmvdecod.dll) on Windows Server 2008 for x64-based Systems Service Pack 2:
Windows6.0-KB2803821-v2-x64.msu
wmv9vcm.dll (codec) on Windows Server 2008 for x64-based Systems Service Pack 2:
Windows6.0-WindowsMedia-KB2845142-x64-ENU.exe
Installation switches See Microsoft Knowledge Base Article 934307
Restart requirement In some cases, this update does not require a restart. If the required files are being used, this update will require a restart. If this behavior occurs, a message appears that advises you to restart.
Removal information WUSA.exe does not support uninstall of updates. To uninstall an update installed by WUSA, click Control Panel, and then click Security. Under Windows Update, click View installed updates and select from the list of updates.
File information See Microsoft Knowledge Base Article 2847883
Registry key verification Note A registry key does not exist to validate the presence of this update.

Windows 7 (all editions)

Reference Table

The following table contains the security update information for this software.

Security update file name Windows Media Player 12 (wmvdecod.dll) on Windows 7 for 32-bit Systems Service Pack 1:
Windows6.1-KB2803821-v2-x86.msu
Windows Media Player 12 (wmvdecod.dll) on Windows 7 for x64-based Systems Service Pack 1:
Windows6.1-KB2803821-v2-x64.msu
Installation switches See Microsoft Knowledge Base Article 934307
Restart requirement In some cases, this update does not require a restart. If the required files are being used, this update will require a restart. If this behavior occurs, a message appears that advises you to restart.
Removal information To uninstall an update installed by WUSA, use the /Uninstall setup switch or click Control Panel, click System and Security, and then under Windows Update, click View installed updates and select from the list of updates.
File information See Microsoft Knowledge Base Article 2847883
Registry key verification Note A registry key does not exist to validate the presence of this update.

Windows Server 2008 R2 (all editions)

Reference Table

The following table contains the security update information for this software.

Security update file name For Windows Media Player 12 (wmvdecod.dll) on Windows Server 2008 R2 for x64-based Systems Service Pack 1:
Windows6.1-KB2803821-v2-x64.msu
Installation switches See Microsoft Knowledge Base Article 934307
Restart requirement In some cases, this update does not require a restart. If the required files are being used, this update will require a restart. If this behavior occurs, a message appears that advises you to restart.
Removal i nformation To uninstall an update installed by WUSA, use the /Uninstall setup switch or click Control Panel, click System and Security, and then under Windows Update, click View installed updates and select from the list of updates.
File information See Microsoft Knowledge Base Article 2847883
Registry k ey v erification Note A registry key does not exist to validate the presence of this update.

Windows 8 (all editions)

Reference Table

The following table contains the security update information for this software.

Security update file name Windows Media Player 12 (wmvdecod.dll) on Windows 8 for 32-bit Systems:
Windows8-RT-KB2803821-x86.msu
Windows Media Player 12 (wmvdecod.dll) on Windows 8 for 64-bit Systems:
Windows8-RT-KB2803821-x64.msu
Installation switches See Microsoft Knowledge Base Article 934307
Restart requirement In some cases, this update does not require a restart. If the required files are being used, this update will require a restart. If this behavior occurs, a message appears that advises you to restart.
Removal information To uninstall an update installed by WUSA, use the /Uninstall setup switch or click Control Panel, click System and Security, click Windows Update, and then under See also, click Installed updates and select from the list of updates.
File information See Microsoft Knowledge Base Article 2847883
Registry key verification Note A registry key does not exist to validate the presence of this update.

Windows Server 2012 (all editions)

Reference Table

The following table contains the security update information for this software.

Security update file name For Windows Media Player 12 (wmvdecod.dll) on all supported editions of Windows Server 2012:
Windows8-RT-KB2803821-arm.msu
Installation switches See Microsoft Knowledge Base Article 934307
Restart requirement In some cases, this update does not require a restart. If the required files are being used, this update will require a restart. If this behavior occurs, a message appears that advises you to restart.
Removal information To uninstall an update installed by WUSA, use the /Uninstall setup switch or click Control Panel, click System and Security, click Windows Update, and then under See also, click Installed updates and select from the list of updates.
File information See Microsoft Knowledge Base Article 2847883
Registry key verification Note A registry key does not exist to validate the presence of this update.

Windows RT (all editions)

The following table contains the security update information for this software.

Deployment This update is available via Windows Update only.
R estart Requirement Yes, you must restart your system after you apply this security update.
Removal Information Click Control Panel, click System and Security, click Windows Update, and then under See also, click Installed updates and select from the list of updates.
File Information See Microsoft Knowledge Base Article 2847883

Other Information

Acknowledgments

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

  • An anonymous researcher, working with HP'sZero Day Initiative, for reporting the WMV Video Decoder Remote Code Execution Vulnerability (CVE-2013-3127)

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 go to the active protections websites provided by program partners, listed in Microsoft Active Protections Program (MAPP) Partners.

Support

How to obtain help and support for this security update

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 9, 2013): Bulletin published.
  • V2.0 (August 13, 2013): Bulletin revised to rerelease the 2803821 update for Windows 7 and Windows 2008 R2. Windows 7 and Windows Server 2008 R2 customers should install the rereleased update. See the Update FAQ for more information.
  • V3.0 (August 27, 2013): Bulletin revised to rerelease security update 2803821 for Windows XP, Windows Server 2003, Windows Vista, and Windows Server 2008; security update 2834902 for Windows XP and Windows Server 2003; security update 2834903 for Windows XP; security update 2834904 for Windows XP and Windows Server 2003; and security update 2834905 for Windows XP. Windows XP, Windows Server 2003, Windows Vista, and Windows Server 2008 customers should install the rereleased updates. See the Update FAQ for more information.

Built at 2014-04-18T13:49:36Z-07:00

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