Microsoft Security Bulletin MS08-070 - Critical Vulnerabilities in Visual Basic 6.0 Runtime Extended Files (ActiveX Controls) Could Allow Remote Code Execution (932349)

Microsoft Security Bulletin MS08-070 - Critical
Vulnerabilities in Visual Basic 6.0 Runtime Extended Files (ActiveX Controls) Could Allow Remote Code Execution (932349)
Published: December 9, 2008

Version: 1.0
General Information
Executive Summary

This security update resolves five privately reported vulnerabilities and one publicly disclosed vulnerability in the ActiveX controls for the Microsoft Visual Basic 6.0 Runtime Extended Files. These vulnerabilities could allow remote code execution if a user browsed a Web site that contains specially crafted content. 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 supported components of the Microsoft Visual Basic 6.0 Runtime Extended Files; all supported editions of Microsoft Visual Studio .NET 2002, Microsoft Visual Studio .NET 2003, Microsoft Visual FoxPro 8.0, Microsoft Visual FoxPro 9.0, Microsoft Office Project 2003, Microsoft Office Project 2007; and the Chinese Simplified (China), Chinese Pan (Hong Kong), Chinese Traditional (Taiwan), and Korean versions of Microsoft Office FrontPage 2002. For more information, see the subsection, Affected and Non-Affected Software, in this section.

The security update addresses the vulnerabilities by improving validation and error handling within the ActiveX controls. For more information about the vulnerabilities, 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. Microsoft Knowledge Base Article 932349 documents the currently known issues that customers may experience when installing this security update. The article also documents recommended solutions for these issues.
Top of sectionTop of section
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
Software Maximum Security Impact Aggregate Severity Rating Bulletins Replaced by this Update
Microsoft Developer Tools

Microsoft Visual Basic 6.0 Runtime Extended Files
(KB926857)

Remote Code Execution

Critical

None

Microsoft Visual Studio .NET 2002 Service Pack 1
(KB958392)

Remote Code Execution

Critical

None

Microsoft Visual Studio .NET 2003 Service Pack 1
(KB958393)

Remote Code Execution

Critical

None

Microsoft Visual FoxPro 8.0 Service Pack 1
(KB958369)

Remote Code Execution

Critical

None

Microsoft Visual FoxPro 9.0 Service Pack 1
(KB958370)

Remote Code Execution

Critical

None

Microsoft Visual FoxPro 9.0 Service Pack 2
(KB958371)

Remote Code Execution

Critical

None
Microsoft Office Software

Microsoft Office FrontPage 2002 Service Pack 3*
(KB957797)

Remote Code Execution

Critical

None

Microsoft Office Project 2003 Service Pack 3
(KB949045)

Remote Code Execution

Critical

None

Microsoft Office Project 2007
(KB949046)

Microsoft Office Project 2007 Service Pack 1
(KB949046)

Remote Code Execution

Critical

None

*This update only applies to FrontPage 2002 Service Pack 3 versions in Chinese Simplified (China), Chinese Pan (Hong Kong), Chinese Traditional (Taiwan), and Korean.

Non-Affected Software
Software

Microsoft Visual Studio 2005 Service Pack 1

Microsoft Visual Studio 2008

Microsoft Visual Studio 2008 Service Pack 1

Microsoft Office FrontPage 2000 Service Pack 3

Microsoft Office FrontPage 2003 Service Pack 3

Microsoft Expression Web

Microsoft Expression Web 2

Microsoft Project 2000 Service Release 1

Microsoft Project 2002 Service Pack 1

Microsoft Office Project Server 2003 Service Pack 3

Microsoft Office Project Portfolio Server 2007

Microsoft Office Project Portfolio Server 2007 Service Pack 1

Microsoft Office Project Server 2007

Microsoft Office Project Server 2007 Service Pack 1
Top of sectionTop of section

Frequently Asked Questions (FAQ) Related to This Security Update

Where are the file information details?
The file information details can be found in Microsoft Knowledge Base Article 932349.

What are the Visual Basic 6.0 Runtime Extended Files?
The Visual Basic 6.0 Runtime Extended Files include select ActiveX controls, libraries, and tools delivered with the Visual Basic 6.0 Integrated Development Environment (IDE) media and as an online release. Typically, either Visual Basic 6.0 IDE or Microsoft.com installs these files on the development system. The developer then redistributes these files with their applications. Although, as of April 8, 2008, support for Visual Basic 6.0 IDE has ended, Microsoft still offers support for select runtime extended files that are distributed with applications. For more information on support for the Visual Basic 6.0 Runtime Extended Files, please see Support Statement for Visual Basic 6.0 on Windows Vista and Windows Server 2008.

I am a third-party application developer and I use the ActiveX control in my application. Is my application vulnerable and how do I update it?
Developers who redistribute the ActiveX control should ensure that they update the version of the ActiveX control installed with their application by downloading the update provided in this bulletin. For more information on best practices on redistributed component use, please see Microsoft Knowledge Base Article 835322 and Isolated Applications and Side-by-side Assemblies.

I am developing software which contains the redistributable ActiveX control. What do I do?
You should install the security update included in this security bulletin for your development software. If you have redistributed ActiveX control with your application, you should issue an updated version of your application to your customers with the updated version of this file included in the download of this security update for your development software.

What are the known issues that customers may experience when installing this security update?
Microsoft Knowledge Base Article 932349 documents the currently known issues that customers may experience when they install this security update. The article also documents recommended solutions for these issues.

Does this update contain any security-related changes to functionality?
Yes. Besides the changes that are listed in the Frequently Asked Questions (FAQ) subsection for the specific vulnerability entry under the section, Vulnerability Information, this update includes defense-in-depth changes to the Winsock Control, mswinsck.ocx. By default, Internet Explorer will not instantiate the Winsock ActiveX Control as it is not marked as safe for scripting. Thus, by default, customers are not at risk from a Web-based attack. However, customers may be at risk via third-party applications that distribute and use mswinsck.ocx.

Why does this update address several reported security vulnerabilities?
This update contains support for several vulnerabilities because the modifications that are required to address these issues are located in related files. Instead of having to install several updates that are almost the same, customers need to install this update only.

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. 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 Microsoft Support Lifecycle. For more information about the extended security update support period for these software versions or editions, visit Microsoft Product Support Services.

Customers who require custom support for older releases 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 Microsoft Worldwide Information, 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.
Top of sectionTop of section
Vulnerability Information

Severity Ratings and Vulnerability Identifiers
Vulnerability Severity Rating and Maximum Security Impact by Affected Software
Affected Software DataGrid Control Memory Corruption Vulnerability - CVE-2008-4252 FlexGrid Control Memory Corruption Vulnerability - CVE-2008-4253 Hierarchical FlexGrid Control Memory Corruption Vulnerability - CVE-2008-4254 Windows Common AVI Parsing Overflow Vulnerability - CVE-2008-4255 Charts Control Memory Corruption Vulnerability - CVE-2008-4256 Masked Edit Control Memory Corruption Vulnerability - CVE-2008-3704 Aggregate Severity Rating
Microsoft Developer Tools

Microsoft Visual Basic 6.0 Runtime Extended Files

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical

Microsoft Visual Studio .NET 2002 Service Pack 1

Not applicable

Not applicable

Not applicable

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical

Microsoft Visual Studio .NET 2003 Service Pack 1

Not applicable

Not applicable

Not applicable

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical

Microsoft Visual FoxPro 8.0 Service Pack 1

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical

Microsoft Visual FoxPro 9.0 Service Pack 1

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical

Microsoft Visual FoxPro 9.0 Service Pack 2

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical
Microsoft Office Software

Microsoft Office FrontPage 2002 Service Pack 3

Not applicable

Critical
Remote Code Execution

Not applicable

Not applicable

Not applicable

Not applicable

Critical

Microsoft Office Project 2003 Service Pack 3

Not applicable

Critical
Remote Code Execution

Not applicable

Critical
Remote Code Execution

Not applicable

Not applicable

Critical

Microsoft Office Project 2007 and Microsoft Office Project 2007 Service Pack 1

Not applicable

Not applicable

Not applicable

Critical
Remote Code Execution

Not applicable

Not applicable

Critical
Top of sectionTop of section

DataGrid Control Memory Corruption Vulnerability - CVE-2008-4252

A remote code execution vulnerability exists in the DataGrid ActiveX Control for Visual Basic 6. An attacker could exploit the vulnerability by constructing a specially crafted Web page. When a user views the Web page, the vulnerability could allow remote code execution. An attacker who successfully exploited this vulnerability could gain the same user rights as the logged-on user.

To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2008-4252.

Mitigating Factors for DataGrid Control Memory Corruption Vulnerability - CVE-2008-4252

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:
•

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.
•

By default, Internet Explorer on Windows Server 2003 and Windows Server 2008 runs in a restricted mode that is known as Enhanced Security Configuration. This mode sets the security level for the Internet zone to High. This is a mitigating factor for Web sites that you have not added to the Internet Explorer Trusted sites zone. See the FAQ subsection of this vulnerability section for more information about Internet Explorer Enhanced Security Configuration.
•

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.
•

By default, all supported versions of Microsoft Outlook and Microsoft Outlook Express open HTML e-mail messages in the Restricted sites zone. The Restricted sites zone helps mitigate attacks that could try to exploit this vulnerability by preventing Active Scripting and ActiveX controls from being used when reading HTML e-mail messages. However, if a user clicks a link in an e-mail message, the user could still be vulnerable to exploitation of this vulnerability through the Web-based attack scenario.
Top of sectionTop of section

Workarounds for DataGrid Control Memory Corruption Vulnerability - CVE-2008-4252

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:
•

Prevent DataGrid ActiveX Control from running in Internet Explorer

You can disable attempts to instantiate a COM object in Internet Explorer by setting the kill bit for the control in the registry.

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.

For detailed steps that you can use to prevent an ActiveX control from running in Internet Explorer, see Microsoft Knowledge Base Article 240797.

Follow these steps in this article to create a Compatibility Flags value in the registry to prevent a COM object from being instantiated in Internet Explorer.

Replace {cde57a43-8b86-11d0-b3c6-00a0c90aea82} below with the Class Identifiers found in this section.

To set the kill bit for a CLSID with a value of {cde57a43-8b86-11d0-b3c6-00a0c90aea82}, paste the following text in a text editor such as Notepad. Then, save the file by using the .reg file name extension.

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{cde57a43-8b86-11d0-b3c6-00a0c90aea82}]
"Compatibility Flags"=dword:00000400

You can apply this .reg file to individual systems by double-clicking it. You can also apply it across domains by using Group Policy.

For more information about Group Policy, visit the following Microsoft Web sites:
•

Group Policy collection
•

What is Group Policy Object Editor?
•

Core Group Policy Tools and Settings

Note You must restart Internet Explorer for your changes to take effect.

Impact of workaround. Web sites that require the DataGrid ActiveX Control may no longer function correctly.

How to undo the workaround.

Paste the following text in a text editor such as Notepad. Then, save the file by using the .reg file name extension.

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{cde57a43-8b86-11d0-b3c6-00a0c90aea82}]
"Compatibility Flags"=-

You can apply this .reg file to individual systems by double-clicking it. You can also apply it across domains by using Group Policy. For more information about Group Policy, visit the following Microsoft Web sites:
•

Group Policy collection
•

What is Group Policy Object Editor?
•

Core Group Policy tools and settings

Note You must restart Internet Explorer for your changes to take effect.
Top of sectionTop of section

FAQ for DataGrid Control Memory Corruption Vulnerability - CVE-2008-4252

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. 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.

What causes the vulnerability?
When the ActiveX control is used in Internet Explorer, the control may corrupt the system state in such a way that an attacker could run arbitrary code.

What might an attacker use the vulnerability to do?
If a user is logged on with administrative user rights, an attacker could take complete control of the 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 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 Web site that is designed to invoke the ActiveX control through Internet Explorer. This can also include compromised Web sites and Web sites that accept or host user-provided content or advertisements. These Web sites 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 in an Instant Messenger request that takes users to the attacker's Web site. It could also be possible to display specially crafted Web content by using banner advertisements or by using other methods to deliver Web content to affected systems.

What systems are primarily at risk from the vulnerability?
This vulnerability requires that a user be logged on and visit a Web site for any malicious action to occur. Therefore, any systems where Internet Explorer is used frequently, such as workstations or terminal servers, are at the most risk from this vulnerability. Servers could be at more risk if administrators allow users to log on to servers and to run programs. However, best practices strongly discourage allowing this.

I am running Internet Explorer for Windows Server 2003 or Windows Server 2008. Does this mitigate this vulnerability?
Yes. By default, Internet Explorer on Windows Server 2003 and Windows Server 2008 runs in a restricted mode that is known as Enhanced Security Configuration. Enhanced Security Configuration is a group of preconfigured settings in Internet Explorer that can reduce the likelihood of a user or administrator downloading and running specially crafted Web content on a server. This is a mitigating factor for Web sites that you have not added to the Internet Explorer Trusted sites zone. See also Managing Internet Explorer Enhanced Security Configuration.

What is the ActiveX opt-in feature in Windows Internet Explorer 7?
Windows Internet Explorer 7 includes an ActiveX opt-in feature, which means that nearly all pre-installed ActiveX controls are off by default. Users are prompted by the Information Bar before they can instantiate a previously installed ActiveX control that has not yet been used on the Internet. This enables a user to permit or deny access on a control-by-control basis. For more information about this and other new features, see the Windows Internet Explorer 7 features page.

What does the update do?
The update removes the vulnerability by handling errors for improperly initialized objects within the ActiveX Control.

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.
Top of sectionTop of section
Top of sectionTop of section

FlexGrid Control Memory Corruption Vulnerability - CVE-2008-4253

A remote code execution vulnerability exists in the FlexGrid ActiveX Control for Visual Basic 6. An attacker could exploit the vulnerability by constructing a specially crafted Web page. When a user views the Web page, the vulnerability could allow remote code execution. An attacker who successfully exploited this vulnerability could gain the same user rights as the logged-on user.

To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2008-4253.

Mitigating Factors for FlexGrid Control Memory Corruption Vulnerability - CVE-2008-4253

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:
•

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.
•

By default, Internet Explorer on Windows Server 2003 and Windows Server 2008 runs in a restricted mode that is known as Enhanced Security Configuration. This mode sets the security level for the Internet zone to High. This is a mitigating factor for Web sites that you have not added to the Internet Explorer Trusted sites zone. See the FAQ subsection of this vulnerability section for more information about Internet Explorer Enhanced Security Configuration.
•

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.
•

By default, all supported versions of Microsoft Outlook and Microsoft Outlook Express open HTML e-mail messages in the Restricted sites zone. The Restricted sites zone helps mitigate attacks that could try to exploit this vulnerability by preventing Active Scripting and ActiveX controls from being used when reading HTML e-mail messages. However, if a user clicks a link in an e-mail message, the user could still be vulnerable to exploitation of this vulnerability through the Web-based attack scenario.
Top of sectionTop of section

Workarounds for FlexGrid Control Memory Corruption Vulnerability - CVE-2008-4253

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:
•

Prevent FlexGrid ActiveX Control from running in Internet Explorer

You can disable attempts to instantiate a COM object in Internet Explorer by setting the kill bit for the control in the registry.

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.

For detailed steps that you can use to prevent an ActiveX control from running in Internet Explorer, see Microsoft Knowledge Base Article 240797.

Follow these steps in this article to create a Compatibility Flags value in the registry to prevent a COM object from being instantiated in Internet Explorer.

Replace {6262d3a0-531b-11cf-91f6-c2863c385e30} below with the Class Identifiers found in this section.

To set the kill bit for a CLSID with a value of {6262d3a0-531b-11cf-91f6-c2863c385e30}, paste the following text in a text editor such as Notepad. Then, save the file by using the .reg file name extension.

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{6262d3a0-531b-11cf-91f6-c2863c385e30}]
"Compatibility Flags"=dword:00000400

You can apply this .reg file to individual systems by double-clicking it. You can also apply it across domains by using Group Policy.

For more information about Group Policy, visit the following Microsoft Web sites:
•

Group Policy collection
•

What is Group Policy Object Editor?
•

Core Group Policy Tools and Settings

Note You must restart Internet Explorer for your changes to take effect.

Impact of workaround. Web sites that require the FlexGrid ActiveX Control may no longer function correctly.

How to undo the workaround.

Paste the following text in a text editor such as Notepad. Then, save the file by using the .reg file name extension.

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{6262d3a0-531b-11cf-91f6-c2863c385e30}]
"Compatibility Flags"=-

You can apply this .reg file to individual systems by double-clicking it. You can also apply it across domains by using Group Policy. For more information about Group Policy, visit the following Microsoft Web sites:
•

Group Policy collection
•

What is Group Policy Object Editor?
•

Core Group Policy tools and settings

Note You must restart Internet Explorer for your changes to take effect.
Top of sectionTop of section

FAQ for FlexGrid Control Memory Corruption Vulnerability - CVE-2008-4253

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. 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.

What causes the vulnerability?
When the ActiveX control is used in Internet Explorer, the control may corrupt the system state in such a way that an attacker could run arbitrary code.

What might an attacker use the vulnerability to do?
If a user is logged on with administrative user rights, an attacker could take complete control of the 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 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 Web site that is designed to invoke the ActiveX control through Internet Explorer. This can also include compromised Web sites and Web sites that accept or host user-provided content or advertisements. These Web sites 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 in an Instant Messenger request that takes users to the attacker's Web site. It could also be possible to display specially crafted Web content by using banner advertisements or by using other methods to deliver Web content to affected systems.

What systems are primarily at risk from the vulnerability?
This vulnerability requires that a user be logged on and visit a Web site for any malicious action to occur. Therefore, any systems where Internet Explorer is used frequently, such as workstations or terminal servers, are at the most risk from this vulnerability. Servers could be at more risk if administrators allow users to log on to servers and to run programs. However, best practices strongly discourage allowing this.

I am running Internet Explorer for Windows Server 2003 or Windows Server 2008. Does this mitigate this vulnerability?
Yes. By default, Internet Explorer on Windows Server 2003 and Windows Server 2008 runs in a restricted mode that is known as Enhanced Security Configuration. Enhanced Security Configuration is a group of preconfigured settings in Internet Explorer that can reduce the likelihood of a user or administrator downloading and running specially crafted Web content on a server. This is a mitigating factor for Web sites that you have not added to the Internet Explorer Trusted sites zone. See also Managing Internet Explorer Enhanced Security Configuration.

What is the ActiveX opt-in feature in Windows Internet Explorer 7?
Windows Internet Explorer 7 includes an ActiveX opt-in feature, which means that nearly all pre-installed ActiveX controls are off by default. Users are prompted by the Information Bar before they can instantiate a previously installed ActiveX control that has not yet been used on the Internet. This enables a user to permit or deny access on a control-by-control basis. For more information about this and other new features, see the Windows Internet Explorer 7 features page.

What does the update do?
The update removes the vulnerability by handling errors for improperly initialized objects within the ActiveX control.

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.
Top of sectionTop of section
Top of sectionTop of section

Hierarchical FlexGrid Control Memory Corruption Vulnerability - CVE-2008-4254

A remote code execution vulnerability exists in the Hierarchical FlexGrid ActiveX Control for Visual Basic 6. An attacker could exploit the vulnerability by constructing a specially crafted Web page. When a user views the Web page, the vulnerability could allow remote code execution. An attacker who successfully exploited this vulnerability could gain the same user rights as the logged-on user.

To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2008-4254.

Mitigating Factors for Hierarchical FlexGrid Control Memory Corruption Vulnerability - CVE-2008-4254

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:
•

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.
•

By default, Internet Explorer on Windows Server 2003 and Windows Server 2008 runs in a restricted mode that is known as Enhanced Security Configuration. This mode sets the security level for the Internet zone to High. This is a mitigating factor for Web sites that you have not added to the Internet Explorer Trusted sites zone. See the FAQ subsection of this vulnerability section for more information about Internet Explorer Enhanced Security Configuration.
•

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.
•

By default, all supported versions of Microsoft Outlook and Microsoft Outlook Express open HTML e-mail messages in the Restricted sites zone. The Restricted sites zone helps mitigate attacks that could try to exploit this vulnerability by preventing Active Scripting and ActiveX controls from being used when reading HTML e-mail messages. However, if a user clicks a link in an e-mail message, the user could still be vulnerable to exploitation of this vulnerability through the Web-based attack scenario.
Top of sectionTop of section

Workarounds for Hierarchical FlexGrid Control Memory Corruption Vulnerability - CVE-2008-4254

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:
•

Prevent Hierarchical FlexGrid ActiveX Control from running in Internet Explorer

You can disable attempts to instantiate a COM object in Internet Explorer by setting the kill bit for the control in the registry.

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.

For detailed steps that you can use to prevent an ActiveX control from running in Internet Explorer, see Microsoft Knowledge Base Article 240797.

Follow these steps in this article to create a Compatibility Flags value in the registry to prevent a COM object from being instantiated in Internet Explorer.

Replace {0ECD9B64-23AA-11d0-B351-00A0C9055D8E} below with the Class Identifiers found in this section.

To set the kill bit for a CLSID with a value of {0ECD9B64-23AA-11d0-B351-00A0C9055D8E}, paste the following text in a text editor such as Notepad. Then, save the file by using the .reg file name extension.

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{0ECD9B64-23AA-11d0-B351-00A0C9055D8E}]
"Compatibility Flags"=dword:00000400

You can apply this .reg file to individual systems by double-clicking it. You can also apply it across domains by using Group Policy.

For more information about Group Policy, visit the following Microsoft Web sites:
•

Group Policy collection
•

What is Group Policy Object Editor?
•

Core Group Policy Tools and Settings

Note You must restart Internet Explorer for your changes to take effect.

Impact of workaround. Web sites that require the Hierarchical FlexGrid ActiveX Control may no longer function correctly.

How to undo the workaround.

Paste the following text in a text editor such as Notepad. Then, save the file by using the .reg file name extension.

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{0ECD9B64-23AA-11d0-B351-00A0C9055D8E}]
"Compatibility Flags"=-

You can apply this .reg file to individual systems by double-clicking it. You can also apply it across domains by using Group Policy. For more information about Group Policy, visit the following Microsoft Web sites:
•

Group Policy collection
•

What is Group Policy Object Editor?
•

Core Group Policy tools and settings

Note You must restart Internet Explorer for your changes to take effect.
Top of sectionTop of section

FAQ for Hierarchical FlexGrid Control Memory Corruption Vulnerability - CVE-2008-4254

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. 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.

What causes the vulnerability?
When the ActiveX control is used in Internet Explorer, the control may corrupt the system state in such a way that an attacker could run arbitrary code.

What might an attacker use the vulnerability to do?
If a user is logged on with administrative user rights, an attacker could take complete control of the 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 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 Web site that is designed to invoke the ActiveX control through Internet Explorer. This can also include compromised Web sites and Web sites that accept or host user-provided content or advertisements. These Web sites 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 in an Instant Messenger request that takes users to the attacker's Web site. It could also be possible to display specially crafted Web content by using banner advertisements or by using other methods to deliver Web content to affected systems.

What systems are primarily at risk from the vulnerability?
This vulnerability requires that a user be logged on and visit a Web site for any malicious action to occur. Therefore, any systems where Internet Explorer is used frequently, such as workstations or terminal servers, are at the most risk from this vulnerability. Servers could be at more risk if administrators allow users to log on to servers and to run programs. However, best practices strongly discourage allowing this.

I am running Internet Explorer for Windows Server 2003 or Windows Server 2008. Does this mitigate this vulnerability?
Yes. By default, Internet Explorer on Windows Server 2003 and Windows Server 2008 runs in a restricted mode that is known as Enhanced Security Configuration. Enhanced Security Configuration is a group of preconfigured settings in Internet Explorer that can reduce the likelihood of a user or administrator downloading and running specially crafted Web content on a server. This is a mitigating factor for Web sites that you have not added to the Internet Explorer Trusted sites zone. See also Managing Internet Explorer Enhanced Security Configuration.

What is the ActiveX opt-in feature in Windows Internet Explorer 7?
Windows Internet Explorer 7 includes an ActiveX opt-in feature, which means that nearly all pre-installed ActiveX controls are off by default. Users are prompted by the Information Bar before they can instantiate a previously installed ActiveX control that has not yet been used on the Internet. This enables a user to permit or deny access on a control-by-control basis. For more information about this and other new features, see the Windows Internet Explorer 7 features page.

What does the update do?
The update removes the vulnerability by handling errors for improperly initialized objects within the ActiveX control.

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.
Top of sectionTop of section
Top of sectionTop of section

Windows Common AVI Parsing Overflow Vulnerability - CVE-2008-4255

A remote code execution vulnerability exists in the Windows Common ActiveX Control for Visual Basic 6. An attacker could exploit the vulnerability by constructing a specially crafted Web page. When a user views the Web page, the vulnerability could allow remote code execution. An attacker who successfully exploited this vulnerability could gain the same user rights as the logged-on user.

To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2008-4255.

Mitigating Factors for Windows Common AVI Parsing Overflow Vulnerability - CVE-2008-4255

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:
•

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.
•

By default, Internet Explorer on Windows Server 2003 and Windows Server 2008 runs in a restricted mode that is known as Enhanced Security Configuration. This mode sets the security level for the Internet zone to High. This is a mitigating factor for Web sites that you have not added to the Internet Explorer Trusted sites zone. See the FAQ subsection of this vulnerability section for more information about Internet Explorer Enhanced Security Configuration.
•

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.
•

By default, all supported versions of Microsoft Outlook and Microsoft Outlook Express open HTML e-mail messages in the Restricted sites zone. The Restricted sites zone helps mitigate attacks that could try to exploit this vulnerability by preventing Active Scripting and ActiveX controls from being used when reading HTML e-mail messages. However, if a user clicks a link in an e-mail message, the user could still be vulnerable to exploitation of this vulnerability through the Web-based attack scenario.
Top of sectionTop of section

Workarounds for Windows Common AVI Parsing Overflow Vulnerability - CVE-2008-4255

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:
•

Prevent Windows Common AVI ActiveX Control from running in Internet Explorer

You can disable attempts to instantiate a COM object in Internet Explorer by setting the kill bit for the control in the registry.

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.

For detailed steps that you can use to prevent an ActiveX control from running in Internet Explorer, see Microsoft Knowledge Base Article 240797.

Follow these steps in this article to create a Compatibility Flags value in the registry to prevent a COM object from being instantiated in Internet Explorer.

Replace {B09DE715-87C1-11d1-8BE3-0000F8754DA1} below with the Class Identifiers found in this section.

To set the kill bit for a CLSID with a value of {B09DE715-87C1-11d1-8BE3-0000F8754DA1}, paste the following text in a text editor such as Notepad. Then, save the file by using the .reg file name extension.

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{B09DE715-87C1-11d1-8BE3-0000F8754DA1}]
"Compatibility Flags"=dword:00000400

You can apply this .reg file to individual systems by double-clicking it. You can also apply it across domains by using Group Policy.

For more information about Group Policy, visit the following Microsoft Web sites:
•

Group Policy collection
•

What is Group Policy Object Editor?
•

Core Group Policy Tools and Settings

Note You must restart Internet Explorer for your changes to take effect.

Impact of workaround. Web sites that require the Windows Common AVI ActiveX Control may no longer function correctly.

How to undo the workaround.

Paste the following text in a text editor such as Notepad. Then, save the file by using the .reg file name extension.

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{B09DE715-87C1-11d1-8BE3-0000F8754DA1}]
"Compatibility Flags"=-

You can apply this .reg file to individual systems by double-clicking it. You can also apply it across domains by using Group Policy. For more information about Group Policy, visit the following Microsoft Web sites:
•

Group Policy collection
•

What is Group Policy Object Editor?
•

Core Group Policy tools and settings

Note You must restart Internet Explorer for your changes to take effect.
Top of sectionTop of section

FAQ for Windows Common AVI Parsing Overflow Vulnerability - CVE-2008-4255

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. 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.

What causes the vulnerability?
The vulnerability is caused by an allocation error when parsing a specially crafted AVI file. The error may corrupt system memory in such a way that an attacker could run arbitrary code.

What might an attacker use the vulnerability to do?
If a user is logged on with administrative user rights, an attacker could take complete control of the 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 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 Web site that is designed to invoke the ActiveX control through Internet Explorer. This can also include compromised Web sites and Web sites that accept or host user-provided content or advertisements. These Web sites 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 in an Instant Messenger request that takes users to the attacker's Web site. It could also be possible to display specially crafted Web content by using banner advertisements or by using other methods to deliver Web content to affected systems.

What systems are primarily at risk from the vulnerability?
This vulnerability requires that a user be logged on and visit a Web site for any malicious action to occur. Therefore, any systems where Internet Explorer is used frequently, such as workstations or terminal servers, are at the most risk from this vulnerability. Servers could be at more risk if administrators allow users to log on to servers and to run programs. However, best practices strongly discourage allowing this.

I am running Internet Explorer for Windows Server 2003 or Windows Server 2008. Does this mitigate this vulnerability?
Yes. By default, Internet Explorer on Windows Server 2003 and Windows Server 2008 runs in a restricted mode that is known as Enhanced Security Configuration. Enhanced Security Configuration is a group of preconfigured settings in Internet Explorer that can reduce the likelihood of a user or administrator downloading and running specially crafted Web content on a server. This is a mitigating factor for Web sites that you have not added to the Internet Explorer Trusted sites zone. See also Managing Internet Explorer Enhanced Security Configuration.

What is the ActiveX opt-in feature in Windows Internet Explorer 7?
Windows Internet Explorer 7 includes an ActiveX opt-in feature, which means that nearly all pre-installed ActiveX controls are off by default. Users are prompted by the Information Bar before they can instantiate a previously installed ActiveX control that has not yet been used on the Internet. This enables a user to permit or deny access on a control-by-control basis. For more information about this and other new features, see the Windows Internet Explorer 7 features page.

What does the update do?
The update removes the vulnerability by validating stream lengths of AVI files parsed by the ActiveX control.

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.
Top of sectionTop of section
Top of sectionTop of section

Charts Control Memory Corruption Vulnerability - CVE-2008-4256

A remote code execution vulnerability exists in the Charts ActiveX Control for Visual Basic 6. An attacker could exploit the vulnerability by constructing a specially crafted Web page. When a user views the Web page, the vulnerability could allow remote code execution. An attacker who successfully exploited this vulnerability could gain the same user rights as the logged-on user.

To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2008-4256.

Mitigating Factors for Charts Control Memory Corruption Vulnerability - CVE-2008-4256

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:
•

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.
•

By default, Internet Explorer on Windows Server 2003 and Windows Server 2008 runs in a restricted mode that is known as Enhanced Security Configuration. This mode sets the security level for the Internet zone to High. This is a mitigating factor for Web sites that you have not added to the Internet Explorer Trusted sites zone. See the FAQ subsection of this vulnerability section for more information about Internet Explorer Enhanced Security Configuration.
•

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.
•

By default, all supported versions of Microsoft Outlook and Microsoft Outlook Express open HTML e-mail messages in the Restricted sites zone. The Restricted sites zone helps mitigate attacks that could try to exploit this vulnerability by preventing Active Scripting and ActiveX controls from being used when reading HTML e-mail messages. However, if a user clicks a link in an e-mail message, the user could still be vulnerable to exploitation of this vulnerability through the Web-based attack scenario.
Top of sectionTop of section

Workarounds for Charts Control Memory Corruption Vulnerability - CVE-2008-4256

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
•

Prevent Charts ActiveX Control from running in Internet Explorer

You can disable attempts to instantiate a COM object in Internet Explorer by setting the kill bit for the control in the registry.

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.

For detailed steps that you can use to prevent an ActiveX control from running in Internet Explorer, see Microsoft Knowledge Base Article 240797.

Follow these steps in this article to create a Compatibility Flags value in the registry to prevent a COM object from being instantiated in Internet Explorer.

Replace {3A2B370C-BA0A-11d1-B137-0000F8753F5D} below with the Class Identifiers found in this section.

To set the kill bit for a CLSID with a value of {3A2B370C-BA0A-11d1-B137-0000F8753F5D}, paste the following text in a text editor such as Notepad. Then, save the file by using the .reg file name extension.

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{3A2B370C-BA0A-11d1-B137-0000F8753F5D}]
"Compatibility Flags"=dword:00000400

You can apply this .reg file to individual systems by double-clicking it. You can also apply it across domains by using Group Policy.

For more information about Group Policy, visit the following Microsoft Web sites:
•

Group Policy collection
•

What is Group Policy Object Editor?
•

Core Group Policy Tools and Settings

Note You must restart Internet Explorer for your changes to take effect.

Impact of workaround. Web sites that require the Charts ActiveX Control may no longer function correctly.

How to undo the workaround.

Paste the following text in a text editor such as Notepad. Then, save the file by using the .reg file name extension.

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{3A2B370C-BA0A-11d1-B137-0000F8753F5D}]
"Compatibility Flags"=-

You can apply this .reg file to individual systems by double-clicking it. You can also apply it across domains by using Group Policy. For more information about Group Policy, visit the following Microsoft Web sites:
•

Group Policy collection
•

What is Group Policy Object Editor?
•

Core Group Policy tools and settings

Note You must restart Internet Explorer for your changes to take effect.
Top of sectionTop of section

FAQ for Charts Control Memory Corruption Vulnerability - CVE-2008-4256

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. 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.

What causes the vulnerability?
When the ActiveX control is used in Internet Explorer, the control may corrupt the system state in such a way that an attacker could run arbitrary code.

What might an attacker use the vulnerability to do?
If a user is logged on with administrative user rights, an attacker could take complete control of the 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 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 Web site that is designed to invoke the ActiveX control through Internet Explorer. This can also include compromised Web sites and Web sites that accept or host user-provided content or advertisements. These Web sites 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 in an Instant Messenger request that takes users to the attacker's Web site. It could also be possible to display specially crafted Web content by using banner advertisements or by using other methods to deliver Web content to affected systems.

What systems are primarily at risk from the vulnerability?
This vulnerability requires that a user be logged on and visit a Web site for any malicious action to occur. Therefore, any systems where Internet Explorer is used frequently, such as workstations or terminal servers, are at the most risk from this vulnerability. Servers could be at more risk if administrators allow users to log on to servers and to run programs. However, best practices strongly discourage allowing this.

I am running Internet Explorer for Windows Server 2003 or Windows Server 2008. Does this mitigate this vulnerability?
Yes. By default, Internet Explorer on Windows Server 2003 and Windows Server 2008 runs in a restricted mode that is known as Enhanced Security Configuration. Enhanced Security Configuration is a group of preconfigured settings in Internet Explorer that can reduce the likelihood of a user or administrator downloading and running specially crafted Web content on a server. This is a mitigating factor for Web sites that you have not added to the Internet Explorer Trusted sites zone. See also Managing Internet Explorer Enhanced Security Configuration.

What is the ActiveX opt-in feature in Windows Internet Explorer 7?
Windows Internet Explorer 7 includes an ActiveX opt-in feature, which means that nearly all pre-installed ActiveX controls are off by default. Users are prompted by the Information Bar before they can instantiate a previously installed ActiveX control that has not yet been used on the Internet. This enables a user to permit or deny access on a control-by-control basis. For more information about this and other new features, see the Windows Internet Explorer 7 features page.

What does the update do?
The update removes the vulnerability by handing errors for improperly initialized objects within the ActiveX control.

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.
Top of sectionTop of section
Top of sectionTop of section

Masked Edit Control Memory Corruption Vulnerability - CVE-2008-3704

A remote code execution vulnerability exists in the Masked Edit ActiveX Control for Visual Basic 6. An attacker could exploit the vulnerability by constructing a specially crafted Web page. When a user views the Web page, the vulnerability could allow remote code execution. An attacker who successfully exploited this vulnerability could gain the same user rights as the logged-on user.

To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2008-3704.

Mitigating Factors for Masked Edit Control Memory Corruption Vulnerability - CVE-2008-3704

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:
•

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.
•

By default, Internet Explorer on Windows Server 2003 and Windows Server 2008 runs in a restricted mode that is known as Enhanced Security Configuration. This mode sets the security level for the Internet zone to High. This is a mitigating factor for Web sites that you have not added to the Internet Explorer Trusted sites zone. See the FAQ subsection of this vulnerability section for more information about Internet Explorer Enhanced Security Configuration.
•

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.
•

By default, all supported versions of Microsoft Outlook and Microsoft Outlook Express open HTML e-mail messages in the Restricted sites zone. The Restricted sites zone helps mitigate attacks that could try to exploit this vulnerability by preventing Active Scripting and ActiveX controls from being used when reading HTML e-mail messages. However, if a user clicks a link in an e-mail message, the user could still be vulnerable to exploitation of this vulnerability through the Web-based attack scenario.
Top of sectionTop of section

Workarounds for Masked Edit Control Memory Corruption Vulnerability - CVE-2008-3704

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:
•

Prevent Masked EditActiveX Control from running in Internet Explorer

You can disable attempts to instantiate a COM object in Internet Explorer by setting the kill bit for the control in the registry.

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.

For detailed steps that you can use to prevent an ActiveX control from running in Internet Explorer, see Microsoft Knowledge Base Article 240797.

Follow these steps in this article to create a Compatibility Flags value in the registry to prevent a COM object from being instantiated in Internet Explorer.

Replace {C932BA85-4374-101B-A56C-00AA003668DC} below with the Class Identifiers found in this section.

To set the kill bit for a CLSID with a value of {C932BA85-4374-101B-A56C-00AA003668DC}, paste the following text in a text editor such as Notepad. Then, save the file by using the .reg file name extension.

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{C932BA85-4374-101B-A56C-00AA003668DC}]
"Compatibility Flags"=dword:00000400

You can apply this .reg file to individual systems by double-clicking it. You can also apply it across domains by using Group Policy.

For more information about Group Policy, visit the following Microsoft Web sites:
•

Group Policy collection
•

What is Group Policy Object Editor?
•

Core Group Policy Tools and Settings

Note You must restart Internet Explorer for your changes to take effect.

Impact of workaround. Web sites that require the Charts ActiveX Control may no longer function correctly.

How to undo the workaround.

Paste the following text in a text editor such as Notepad. Then, save the file by using the .reg file name extension.

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{C932BA85-4374-101B-A56C-00AA003668DC}]
"Compatibility Flags"=-

You can apply this .reg file to individual systems by double-clicking it. You can also apply it across domains by using Group Policy. For more information about Group Policy, visit the following Microsoft Web sites:
•

Group Policy collection
•

What is Group Policy Object Editor?
•

Core Group Policy tools and settings

Note You must restart Internet Explorer for your changes to take effect.
Top of sectionTop of section

FAQ for Masked Edit Control Memory Corruption Vulnerability - CVE-2008-3704

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. 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.

What causes the vulnerability?
The ActiveX control does not correctly handle property values, which causes a buffer overrun when used in Internet Explorer that could allow an attacker to run arbitrary code.

What might an attacker use the vulnerability to do?
If a user is logged on with administrative user rights, an attacker could take complete control of the 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 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 Web site that is designed to invoke the ActiveX control through Internet Explorer. This can also include compromised Web sites and Web sites that accept or host user-provided content or advertisements. These Web sites 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 in an Instant Messenger request that takes users to the attacker's Web site. It could also be possible to display specially crafted Web content by using banner advertisements or by using other methods to deliver Web content to affected systems.

What systems are primarily at risk from the vulnerability?
This vulnerability requires that a user be logged on and visit a Web site for any malicious action to occur. Therefore, any systems where Internet Explorer is used frequently, such as workstations or terminal servers, are at the most risk from this vulnerability. Servers could be at more risk if administrators allow users to log on to servers and to run programs. However, best practices strongly discourage allowing this.

I am running Internet Explorer for Windows Server 2003 or Windows Server 2008. Does this mitigate this vulnerability?
Yes. By default, Internet Explorer on Windows Server 2003 and Windows Server 2008 runs in a restricted mode that is known as Enhanced Security Configuration. Enhanced Security Configuration is a group of preconfigured settings in Internet Explorer that can reduce the likelihood of a user or administrator downloading and running specially crafted Web content on a server. This is a mitigating factor for Web sites that you have not added to the Internet Explorer Trusted sites zone. See also Managing Internet Explorer Enhanced Security Configuration.

What is the ActiveX opt-in feature in Windows Internet Explorer 7?
Windows Internet Explorer 7 includes an ActiveX opt-in feature, which means that nearly all pre-installed ActiveX controls are off by default. Users are prompted by the Information Bar before they can instantiate a previously installed ActiveX control that has not yet been used on the Internet. This enables a user to permit or deny access on a control-by-control basis. For more information about this and other new features, see the Windows Internet Explorer 7 features page.

What does the update do?
The update removes the vulnerability by validating property values with boundary checks when the ActiveX control is used in Internet Explorer.

When this security bulletin was issued, had this vulnerability been publicly disclosed?
Yes. This vulnerability had been publicly disclosed when this security bulletin was originally issued. It has been assigned the Common Vulnerability and Exposure number CVE-2008-3704.

When this security bulletin was issued, had Microsoft received any reports that this vulnerability was being exploited?
Yes. Microsoft is aware of limited, targeted attacks attempting to exploit the vulnerability.

Other Information
Acknowledgments

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

ADLab of VenusTech for reporting the DataGrid Control Memory Corruption Vulnerability (CVE-2008-4252)
•

ADLab of VenusTech for reporting the FlexGrid Control Memory Corruption Vulnerability (CVE-2008-4253)
•

ADLab of VenusTech for reporting the Hierarchical FlexGrid Control Memory Corruption Vulnerability (CVE-2008-4254)
•

Jason Medeiros of Affiliated Computer Services for reporting the Hierarchical FlexGrid Control Memory Corruption Vulnerability (CVE-2008-4254)
•

Carsten Eiram of Secunia Research for reporting the Hierarchical FlexGrid Control Memory Corruption Vulnerability (CVE-2008-4254)
•

Mark Dowd, working with McAfee Avert Labs, for reporting the Windows Common AVI Parsing Overflow Vulnerability (CVE-2008-4255)
•

Brett Moore of Insomnia Security for reporting the Windows Common AVI Parsing Overflow Vulnerability (CVE-2008-4255)
•

CHkr_D591, working with TippingPoint and the Zero Day Initiative, for reporting the Windows Common AVI Parsing Overflow Vulnerability (CVE-2008-4255)
•

Michal Bucko, working with CERT/CC, for reporting the Charts Control Memory Corruption Vulnerability (CVE-2008-4256)
•

Symantec’s Security Intelligence Analysis Team for working with us on the Masked Edit Control Memory Corruption Vulnerability (CVE-2008-3704)
Top of sectionTop of section
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 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.