MS11-026: Vulnerability in MHTML could allow information disclosure: April 12, 2011

Microsoft has released security bulletin MS11-026. To view the complete security bulletin, visit one of the following Microsoft websites:

• Home users:
  http://www.microsoft.com/security/pc-security/bulletins/201104.aspx

  (http://www.microsoft.com/security/pc-security/bulletins/201104.aspx)
  Skip the details: Download the updates for your home computer or laptop from the Microsoft Update website now:
  http://update.microsoft.com/microsoftupdate/

  (http://update.microsoft.com/microsoftupdate/)
• IT professionals:
  http://www.microsoft.com/technet/security/bulletin/MS11-026.mspx

  (http://www.microsoft.com/technet/security/bulletin/MS11-026.mspx)

How to obtain help and support for this security update

Help installing updates: Support for Microsoft Update

Security solutions for IT professionals: TechNet Security Troubleshooting and Support

Help protect your computer that is running Windows from viruses and malware: Virus Solution and Security Center

Local support according to your country: International Support

The Fix it solution that is described in this section is not intended to be a replacement for any security update. We recommend that you always install the latest security updates. However, we offer this Fix it solution as a workaround option for some scenarios. 

For more information about this workaround, visit the following Microsoft Security Bulletin webpage: The bulletin provides more information about the issue, including the following:

• The scenarios in which you might apply or disable the workaround.
• How to manually apply the workaround.

Specifically, to see this information, expand the MHTML Mime-Formatted Request Vulnerability section, and then see the Workarounds for MHTML Mime-Formatted Request Vulnerability section.

To enable or disable this Fix it solution, click the Fix it button or link under the Enable heading or under the Disable heading. Click Run in the File Download dialog box, and then follow the steps in the Fix it wizard.
Notes

• These wizards may be in English only. However, the automatic fixes also work for other language versions of Windows.
• If you are not on the computer that has the problem, you can save the automatic fix to a flash drive or to a CD, and then you can run it on the computer that has the problem.

The English (United States) version of this software update installs files that have the attributes that are listed in the following tables. The dates and times for these files are listed in Coordinated Universal Time (UTC). The dates and times for these files on your local computer are displayed in your local time and with your current daylight saving time (DST) bias. Additionally, the dates and times may change when you perform certain operations on the files.

Windows XP and Windows Server 2003 file information

• The files that apply to a specific milestone (SPn) and service branch (QFE, GDR) are noted in the "SP requirement" and "Service branch" columns.
• GDR service branches contain only those fixes that are widely released to address widespread, critical issues. QFE service branches contain hotfixes in addition to widely released fixes.
• In addition to the files that are listed in these tables, this software update also installs an associated security catalog file (KBnumber.cat) that is signed with a Microsoft digital signature.

For all supported x86-based versions of Windows XP

For all supported x64-based versions of Windows Server 2003 and of Windows XP Professional x64 edition

For all supported x86-based versions of Windows Server 2003

For all supported IA-64-based versions of Windows Server 2003

Windows Vista and Windows Server 2008 file information

• The files that apply to a specific product, milestone (SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table:
  Collapse this tableExpand this table

  Version	Product	Milestone	Service branch
  6.0.6001.18xxx	Windows Vista SP1 and Windows Server 2008 SP1	SP1	GDR
  6.0.6001.22xxx	Windows Vista SP1 and Windows Server 2008 SP1	SP1	LDR
  6.0.6002.18xxx	Windows Vista SP2 and Windows Server 2008 SP2	SP2	GDR
  6.0.6002.22xxx	Windows Vista SP2 and Windows Server 2008 SP2	SP2	LDR

• Service Pack 1 is integrated into the release version of Windows Server 2008. Therefore, RTM milestone files apply only to Windows Vista. RTM milestone files have a 6.0.0000.xxxxxx version number.
• GDR service branches contain only those fixes that are widely released to address widespread, critical issues. LDR service branches contain hotfixes in addition to widely released fixes.
• The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately. MUM and MANIFEST files, and the associated security catalog (.cat) files, are critical to maintaining the state of the updated component. The security catalog files (attributes not listed) are signed with a Microsoft digital signature.

For all supported x86-based versions of Windows Vista and Windows Server 2008

For all supported x64-based versions of Windows Vista and Windows Server 2008

For all supported IA-64-based versions of Windows Server 2008

Additional file information for Windows Vista and Windows Server 2008

Additional files for all supported x86-based versions of Windows Vista and Windows Server 2008

Additional files for all supported x64-based versions of Windows Vista and Windows Server 2008

Additional files for all supported IA-64-based versions of Windows Server 2008

Windows 7 and Windows Server 2008 R2 file information

• The files that apply to a specific product, milestone (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table:
  
  Collapse this tableExpand this table

  Version	Product	Milestone	Service branch
  6.1.7600.16xxx	Windows 7 and Windows Server 2008 R2	RTM	GDR
  6.1.7600.20xxx	Windows 7 and Windows Server 2008 R2	RTM	LDR
  6.1.7600.17xxx	Windows 7 and Windows Server 2008 R2	SP1	GDR
  6.1.7600.21xxx	Windows 7 and Windows Server 2008 R2	SP1	LDR

• GDR service branches contain only those fixes that are widely released to address widespread, critical issues. LDR service branches contain hotfixes in addition to widely released fixes.
• The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately in the "Additional file information for Windows 7 and Windows Server 2008 R2" section. MUM and MANIFEST files, and the associated security catalog (.cat) files, are critical to maintaining the state of the updated component. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.

For all supported x86-based versions of Windows 7

For all supported x64-based versions of Windows 7 and Windows Server 2008 R2

For all supported IA-64-based versions of Windows Server 2008 R2

Additional file information for Windows 7 and Windows Server 2008 R2

Additional files for all supported x86-based versions of Windows 7

Additional files for all supported x64-based versions of Windows 7 and Windows Server 2008 R2

Additional files for all supported IA-64-based versions of Windows Server 2008 R2