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  Microsoft Access security vulnerabilities

  ZDI-10-117: Microsoft Office Access AccWizObjects ActiveX Control Uninitialized Imports Remote Code Execution Vulnerability

From:MICROSOFT <secure_(at)_microsoft.com>
Date:14.07.2010
Subject:Microsoft Security Bulletin MS10-044 - Critical Vulnerabilities in Microsoft Office Access ActiveX Controls Could Allow Remote Code Execution (982335)

Microsoft Security Bulletin MS10-044 - Critical
Vulnerabilities in Microsoft Office Access ActiveX Controls Could Allow Remote Code Execution (982335)
Published: July 13, 2010

Version: 1.0
General Information
Executive Summary

This security update resolves two privately reported vulnerabilities in Microsoft Office Access ActiveX Controls. The vulnerabilities could allow remote code execution if a user opened a specially crafted Office file or viewed a Web page that instantiated Access ActiveX controls. 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 editions of Microsoft Office Access 2003 and Microsoft Office Access 2007. For more information, see the subsection, Affected and Non-Affected Software, in this section.

The update addresses the vulnerabilities by updating specific Access ActiveX controls and by modifying the way memory is accessed by Microsoft Office and by Internet Explorer when loading Access ActiveX controls. For more information about the vulnerability, see the Frequently Asked Questions (FAQ) subsection for the specific vulnerability entry under the next section, Vulnerability Information.

Recommendation. Microsoft recommends that customers apply the update immediately.

Known Issues. None
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Affected and Non-Affected Software

The following software have been tested to determine which versions or editions are affected. Other versions or editions are either past their support life cycle or are not affected. To determine the support life cycle for your software version or edition, visit Microsoft Support Lifecycle.

Affected Software
Office Suite Component Maximum Security Impact Aggregate Severity Rating Bulletins Replaced by this Update

Microsoft Office 2003 Service Pack 3


Microsoft Office Access 2003 Service Pack 3
(KB981716)


Remote Code Execution


Critical


None

2007 Microsoft Office System Service Pack 1 and 2007 Microsoft Office System Service Pack 2


Microsoft Office Access 2007 Service Pack 1 and Microsoft Office Access 2007 Service Pack 2
(KB979440)


Remote Code Execution


Critical


None

Non-Affected Software
Office Suite Component

Microsoft Office XP Service Pack 3


Microsoft Office Access 2002 Service Pack 3

Microsoft Office 2010 (32-bit editions)


Microsoft Office Access 2010 (32-bit editions)

Microsoft Office 2010 (64-bit editions)


Microsoft Office Access 2010 (64-bit editions)
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Frequently Asked Questions (FAQ) Related to This Security Update

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

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 use the 2007 Microsoft Office System Service Pack 1. Are any additional security features included in this update?
Yes, as part of the servicing model for the 2007 Microsoft Office System, when users of the 2007 Microsoft Office System Service Pack 1 install this update, their systems will be upgraded to security functionality that was initially released with the 2007 Microsoft Office System Service Pack 2. All updates released after April 24, 2009 for the 2007 Microsoft Office System will include these security features, which were introduced in the 2007 Microsoft Office System Service Pack 2. We have thoroughly tested this update, but as with all updates, we recommend that users perform testing appropriate to the environment and configuration of their systems.

The Office component discussed in this article is part of the Office Suite that I have installed on my system; however, I did not choose to install this specific component. Will I be offered this update?
Yes, if the version of the Office Suite installed on your system was delivered with the component discussed in this bulletin, the system will be offered updates for it whether the component is installed or not. The detection logic used to scan for affected systems is designed to check for updates for all components that shipped with the particular Office Suite and offer the updates to a system. Users who choose not to apply an update for a component that is not installed, but is included in their version of the Office Suite, will not increase the security risk of that system. On the other hand, users who do choose to install the update will not have a negative impact on the security or performance of a system.

Does the offer to update a non-vulnerable version of Microsoft Office constitute an issue in the Microsoft update mechanism?
No, the update mechanism is functioning correctly in that it detects a lower version of the files on the system than in the update package and thus, offers the update.

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

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

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

Severity Ratings and Vulnerability Identifiers

The following severity ratings assume the potential maximum impact of the vulnerability. For information regarding the likelihood, within 30 days of this security bulletin's release, of the exploitability of the vulnerability in relation to its severity rating and security impact, please see the Exploitability Index in the July bulletin summary. For more information, see Microsoft Exploitability Index.
Vulnerability Severity Rating and Maximum Security Impact by Affected Software
Affected Software Access ActiveX Control Vulnerability- CVE-2010-0814 ACCWIZ.dll Uninitialized Variable Vulnerability - CVE-2010-1881 Aggregate Severity Rating

Microsoft Office Access 2003 Service Pack 3


Critical
Remote Code Execution


Critical
Remote Code Execution


Critical

Microsoft Office Access 2007 Service Pack 1 and Microsoft Office Access 2007 Service Pack 2


Critical
Remote Code Execution


Not applicable


Critical
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Access ActiveX Control Vulnerability- CVE-2010-0814

A remote code execution vulnerability exists in Access ActiveX controls due to the way that multiple ActiveX controls are loaded by Internet Explorer. An attacker who successfully exploited this vulnerability could run arbitrary code as the logged-on user. 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.

To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2010-0814.

Mitigating Factors for Access ActiveX Control Vulnerability- CVE-2010-0814

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.


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 Office Outlook, Microsoft Outlook Express, Windows Mail, and Windows Live Mail open HTML e-mail messages in the Restricted sites zone, which disables script and ActiveX controls, removing the risk of an attacker being able to use this vulnerability to execute malicious code. 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.


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.
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Workarounds for Access ActiveX Control Vulnerability- CVE-2010-0814

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 COM objects 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. The COM objects that will be prevented from instantiating in Internet Explorer by this workaround are the FieldList and ImexGrid ActiveX controls.

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 a control from running in Internet Explorer, see Microsoft Knowledge Base Article 240797. Follow the steps in this article to create a Compatibility Flags value in the registry to prevent a COM object from being instantiated in Internet Explorer.

To set the kill bit for the CLSIDs with the value of {53230327-172B-11D0-AD40-00A0C90DC8D9} and {53230322-172B-11d0-AD40-00A0C90DC8D9}, 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\{53230327-172B-11D0-AD40-00A0C90DC8D9}]
"Compatibility Flags"=dword:00000400

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{53230322-172B-11d0-AD40-00A0C90DC8D9}]
"Compatibility Flags"=dword:00000400

[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Internet Explorer\ActiveX Compatibility\{53230327-172B-11D0-AD40-00A0C90DC8D9}]
"Compatibility Flags"=dword:00000400

[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Internet Explorer\ActiveX Compatibility\{53230322-172B-11d0-AD40-00A0C90DC8D9}]
"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. The FieldList and ImexGrid controls are used in some of the Access wizards, a feature available in Microsoft Office Access only. After applying this workaround, a subset of wizards may not function properly.

How to undo the workaround. Delete the registry keys previously added in implementing this workaround.


Set Internet and Local intranet security zone settings to "High" to block ActiveX Controls and Active Scripting in these zones

You can help protect against exploitation of this vulnerability by changing your settings for the Internet security zone to block ActiveX controls and Active Scripting. You can do this by setting your browser security to High.

To raise the browsing security level in Internet Explorer, follow these steps:

1.


On the Internet Explorer Tools menu, click Internet Options.

2.


In the Internet Options dialog box, click the Security tab, and then click the Internet icon.

3.


Under Security level for this zone, move the slider to High. This sets the security level for all Web sites you visit to High.

Note If no slider is visible, click Default Level, and then move the slider to High.

Note Setting the level to High may cause some Web sites to work incorrectly. If you have difficulty using a Web site after you change this setting, and you are sure the site is safe to use, you can add that site to your list of trusted sites. This will allow the site to work correctly even with the security setting set to High.

Impact of workaround. There are side effects to blocking ActiveX Controls and Active Scripting. Many Web sites that are on the Internet or on an intranet use ActiveX or Active Scripting to provide additional functionality. For example, an online e-commerce site or banking site may use ActiveX Controls to provide menus, ordering forms, or even account statements. Blocking ActiveX Controls or Active Scripting is a global setting that affects all Internet and intranet sites. If you do not want to block ActiveX Controls or Active Scripting for such sites, use the steps outlined in "Add sites that you trust to the Internet Explorer Trusted sites zone".

How to undo the workaround. In Internet Options, return the slider to your previous setting or click Reset all zones to default level.

Add sites that you trust to the Internet Explorer Trusted sites zone

After you set Internet Explorer to block ActiveX controls and Active Scripting in the Internet zone and in the Local intranet zone, you can add sites that you trust to the Internet Explorer Trusted sites zone. This will allow you to continue to use trusted Web sites exactly as you do today, while helping to protect you from this attack on untrusted sites. We recommend that you add only sites that you trust to the Trusted sites zone.

To do this, follow these steps:

1.


In Internet Explorer, click Tools, click Internet Options, and then click the Security tab.

2.


In the Select a Web content zone to specify its current security settings box, click Trusted Sites, and then click Sites.

3.


If you want to add sites that do not require an encrypted channel, click to clear the Require server verification (https:) for all sites in this zone check box.

4.


In the Add this Web site to the zone box, type the URL of a site that you trust, and then click Add.

5.


Repeat these steps for each site that you want to add to the zone.

6.


Click OK two times to accept the changes and return to Internet Explorer.

Note Add any sites that you trust not to take malicious action on your system. Two in particular that you may want to add are *.windowsupdate.microsoft.com and *.update.microsoft.com. These are the sites that will host the update, and it requires an ActiveX Control to install the update.


Configure Internet Explorer to prompt before running Active Scripting or to disable Active Scripting in the Internet and Local intranet security zone

You can help protect against exploitation of this vulnerability by changing your settings to prompt before running Active Scripting or to disable Active Scripting in the Internet and Local intranet security zone. To do this, follow these steps:

1.


In Internet Explorer, click Internet Options on the Tools menu.

2.


Click the Security tab.

3.


Click Internet, and then click Custom Level.

4.


Under Settings, in the Scripting section, under Active Scripting, click Prompt or Disable, and then click OK.

5.


Click Local intranet, and then click Custom Level.

6.


Under Settings, in the Scripting section, under Active Scripting, click Prompt or Disable, and then click OK.

7.


Click OK two times to return to Internet Explorer.

Note Disabling Active Scripting in the Internet and Local intranet security zones may cause some Web sites to work incorrectly. If you have difficulty using a Web site after you change this setting, and you are sure the site is safe to use, you can add that site to your list of trusted sites. This will allow the site to work correctly.

Impact of workaround. There are side effects to prompting before running Active Scripting. Many Web sites that are on the Internet or on an intranet use Active Scripting to provide additional functionality. For example, an online e-commerce site or banking site may use Active Scripting to provide menus, ordering forms, or even account statements. Prompting before running Active Scripting is a global setting that affects all Internet and intranet sites. You will be prompted frequently when you enable this workaround. For each prompt, if you feel you trust the site that you are visiting, click Yes to run Active Scripting. If you do not want to be prompted for all these sites, use the steps outlined in "Add sites that you trust to the Internet Explorer Trusted sites zone".

How to undo the workaround. In Security Settings, return to your previous settings or else click Reset.

Add sites that you trust to the Internet Explorer Trusted sites zone

After you set Internet Explorer to require a prompt before it runs ActiveX controls and Active Scripting in the Internet zone and in the Local intranet zone, you can add sites that you trust to the Internet Explorer Trusted sites zone. This will allow you to continue to use trusted Web sites exactly as you do today, while helping to protect you from this attack on untrusted sites. We recommend that you add only sites that you trust to the Trusted sites zone.

To do this, follow these steps:

1.


In Internet Explorer, click Tools, click Internet Options, and then click the Security tab.

2.


In the Select a Web content zone to specify its current security settings box, click Trusted Sites, and then click Sites.

3.


If you want to add sites that do not require an encrypted channel, click to clear the Require server verification (https:) for all sites in this zone check box.

4.


In the Add this Web site to the zone box, type the URL of a site that you trust, and then click Add.

5.


Repeat these steps for each site that you want to add to the zone.

6.Click OK two times to accept the changes and return to Internet Explorer.

Note Add any sites that you trust not to take malicious action on your system. Two in particular that you may want to add are *.windowsupdate.microsoft.com and *.update.microsoft.com. These are the sites that will host the update, and it requires an ActiveX Control to install the update.
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FAQ for Access ActiveX Control Vulnerability- CVE-2010-0814

What is the scope of the vulnerability?
This is a remote code execution vulnerability. An attacker who successfully exploited this vulnerability could gain the same user rights as the logged-on 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.

What causes the vulnerability?
A remote code execution vulnerability exists in the way that Internet Explorer handles memory allocation when instantiating a succession of Access ActiveX controls.

What is the ACCWIZ.DLL ActiveX Control?
ACCWIZ.dll (Microsoft Access Wizard Controls) is a runtime component of Microsoft Office Access that provides a library of Access ActiveX controls such as the ImexGrid control and the FieldList control.

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. 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?
Exploitation of this vulnerability requires that a user visit a specially crafted Web site that contains a succession of Access ActiveX controls.

In a Web-based attack scenario, an attacker would have to host a Web site that contains a succession of ActiveX controls that are used to attempt to exploit this vulnerability. In addition, compromised Web sites and Web sites that accept or host user-provided content could contain specially crafted content that could exploit this vulnerability. An attacker would have no way to force users to visit a specially crafted Web site. Instead, an attacker would have to convince them 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.

What systems are primarily at risk from the vulnerability?
Systems where Microsoft Office Access is used, including workstations and terminal servers, are primarily at risk. 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 on 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 does the update do?
The update addresses the vulnerability by modifying the way that Access ActiveX controls are loaded into memory and by updating specific ActiveX controls.

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. This security bulletin addresses the privately disclosed vulnerability as well as additional issues discovered through internal investigations.

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.

ACCWIZ.dll Uninitialized Variable Vulnerability - CVE-2010-1881

A remote code execution vulnerability exists in the way that the FieldList ActiveX control is instantiated by Microsoft Office and Internet Explorer. An attacker who successfully exploited this vulnerability could run arbitrary code as the logged-on user. 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.

To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2010-1881.

Mitigating Factors for ACCWIZ.dll Uninitialized Variable Vulnerability - CVE-2010-1881

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.


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 Office Outlook, Microsoft Outlook Express, and Windows Mail, and Windows Live Mail open HTML e-mail messages in the Restricted sites zone, which disables script and ActiveX controls, removing the risk of an attacker being able to use this vulnerability to execute malicious code. 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. In addition, if a user opens an attachment in an e-mail, the user could still be vulnerable to exploitation when opening a specially crafted Office file.


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.
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Workarounds for ACCWIZ.dll Uninitialized Variable Vulnerability - CVE-2010-1881

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:


Do not open Microsoft Office files that you receive from untrusted sources

Do not open Microsoft Office files that you receive from untrusted sources or that you receive unexpectedly from trusted sources. This vulnerability could be exploited when a user opens a specially crafted file.


Prevent COM objects 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. The COM object that will be prevented from instantiating in Internet Explorer by this workaround is the FieldList ActiveX control.

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 a control from running in Internet Explorer, see Microsoft Knowledge Base Article 240797. Follow the steps in this article to create a Compatibility Flags value in the registry to prevent a COM object from being instantiated in Internet Explorer.

To set the kill bits for the CLSIDs with the values of {53230327-172B-11D0-AD40-00A0C90DC8D9}, 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\{53230327-172B-11D0-AD40-00A0C90DC8D9}]
"Compatibility Flags"=dword:00000400

[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Internet Explorer\ActiveX Compatibility\{53230327-172B-11D0-AD40-00A0C90DC8D9}]
"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. The FieldList control is used in some of the Access wizards, a feature available in Microsoft Office Access only. After applying this workaround, a subset of wizards may not function properly.

How to undo the workaround. Delete the registry keys previously added in implementing this workaround.


Set Internet and Local intranet security zone settings to "High" to block ActiveX Controls and Active Scripting in these zones

You can help protect against exploitation of this vulnerability by changing your settings for the Internet security zone to block ActiveX controls and Active Scripting. You can do this by setting your browser security to High.

To raise the browsing security level in Internet Explorer, follow these steps:

1.


On the Internet Explorer Tools menu, click Internet Options.

2.


In the Internet Options dialog box, click the Security tab, and then click the Internet icon.

3.


Under Security level for this zone, move the slider to High. This sets the security level for all Web sites you visit to High.

Note If no slider is visible, click Default Level, and then move the slider to High.

Note Setting the level to High may cause some Web sites to work incorrectly. If you have difficulty using a Web site after you change this setting, and you are sure the site is safe to use, you can add that site to your list of trusted sites. This will allow the site to work correctly even with the security setting set to High.

Impact of workaround. There are side effects to blocking ActiveX Controls and Active Scripting. Many Web sites that are on the Internet or on an intranet use ActiveX or Active Scripting to provide additional functionality. For example, an online e-commerce site or banking site may use ActiveX Controls to provide menus, ordering forms, or even account statements. Blocking ActiveX Controls or Active Scripting is a global setting that affects all Internet and intranet sites. If you do not want to block ActiveX Controls or Active Scripting for such sites, use the steps outlined in "Add sites that you trust to the Internet Explorer Trusted sites zone".

How to undo the workaround. In Internet Options, return the slider to your previous setting or click Reset all zones to default level.

Add sites that you trust to the Internet Explorer Trusted sites zone

After you set Internet Explorer to block ActiveX controls and Active Scripting in the Internet zone and in the Local intranet zone, you can add sites that you trust to the Internet Explorer Trusted sites zone. This will allow you to continue to use trusted Web sites exactly as you do today, while helping to protect you from this attack on untrusted sites. We recommend that you add only sites that you trust to the Trusted sites zone.

To do this, follow these steps:

1.


In Internet Explorer, click Tools, click Internet Options, and then click the Security tab.

2.


In the Select a Web content zone to specify its current security settings box, click Trusted Sites, and then click Sites.

3.


If you want to add sites that do not require an encrypted channel, click to clear the Require server verification (https:) for all sites in this zone check box.

4.


In the Add this Web site to the zone box, type the URL of a site that you trust, and then click Add.

5.


Repeat these steps for each site that you want to add to the zone.

6.


Click OK two times to accept the changes and return to Internet Explorer.

Note Add any sites that you trust not to take malicious action on your system. Two in particular that you may want to add are *.windowsupdate.microsoft.com and *.update.microsoft.com. These are the sites that will host the update, and it requires an ActiveX Control to install the update.


Configure Internet Explorer to prompt before running Active Scripting or to disable Active Scripting in the Internet and Local intranet security zone

You can help protect against exploitation of this vulnerability by changing your settings to prompt before running Active Scripting or to disable Active Scripting in the Internet and Local intranet security zone. To do this, follow these steps:

1.


In Internet Explorer, click Internet Options on the Tools menu.

2.


Click the Security tab.

3.


Click Internet, and then click Custom Level.

4.


Under Settings, in the Scripting section, under Active Scripting, click Prompt or Disable, and then click OK.

5.


Click Local intranet, and then click Custom Level.

6.


Under Settings, in the Scripting section, under Active Scripting, click Prompt or Disable, and then click OK.

7.


Click OK two times to return to Internet Explorer.

Note Disabling Active Scripting in the Internet and Local intranet security zones may cause some Web sites to work incorrectly. If you have difficulty using a Web site after you change this setting, and you are sure the site is safe to use, you can add that site to your list of trusted sites. This will allow the site to work correctly.

Impact of workaround. There are side effects to prompting before running Active Scripting. Many Web sites that are on the Internet or on an intranet use Active Scripting to provide additional functionality. For example, an online e-commerce site or banking site may use Active Scripting to provide menus, ordering forms, or even account statements. Prompting before running Active Scripting is a global setting that affects all Internet and intranet sites. You will be prompted frequently when you enable this workaround. For each prompt, if you feel you trust the site that you are visiting, click Yes to run Active Scripting. If you do not want to be prompted for all these sites, use the steps outlined in "Add sites that you trust to the Internet Explorer Trusted sites zone".

How to undo the workaround. In Security Settings, return to your previous settings or else click Reset.

Add sites that you trust to the Internet Explorer Trusted sites zone

After you set Internet Explorer to require a prompt before it runs ActiveX controls and Active Scripting in the Internet zone and in the Local intranet zone, you can add sites that you trust to the Internet Explorer Trusted sites zone. This will allow you to continue to use trusted Web sites exactly as you do today, while helping to protect you from this attack on untrusted sites. We recommend that you add only sites that you trust to the Trusted sites zone.

To do this, follow these steps:

1.


In Internet Explorer, click Tools, click Internet Options, and then click the Security tab.

2.


In the Select a Web content zone to specify its current security settings box, click Trusted Sites, and then click Sites.

3.


If you want to add sites that do not require an encrypted channel, click to clear the Require server verification (https:) for all sites in this zone check box.

4.


In the Add this Web site to the zone box, type the URL of a site that you trust, and then click Add.

5.


Repeat these steps for each site that you want to add to the zone.

6.Click OK two times to accept the changes and return to Internet Explorer.

Note Add any sites that you trust not to take malicious action on your system. Two in particular that you may want to add are *.windowsupdate.microsoft.com and *.update.microsoft.com. These are the sites that will host the update, and it requires an ActiveX Control to install the update.
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FAQ for ACCWIZ.dll Uninitialized Variable Vulnerability - CVE-2010-1881

What is the scope of the vulnerability?
This is a remote code execution vulnerability. An attacker who successfully exploited this vulnerability could gain the same user rights as the logged-on 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

What causes the vulnerability?
A memory corruption vulnerability exists in ActiveX controls in the ACCWIZ library that can be taken advantage of by providing a control with specially crafted persisted storage data.

What is the ACCWIZ.DLL ActiveX Control?
ACCWIZ.dll (Microsoft Access Wizard Controls) is a runtime component of Microsoft Office that provides a library of Access ActiveX controls such as the ImexGrid control and the FieldList control.

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. 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?
This vulnerability requires that the affected ActiveX Control be instantiated.

In an e-mail attack scenario, an attacker could exploit the vulnerability by sending a specially crafted file to the user and by convincing the user to open the file. In addition, an attacker could exploit the vulnerability by sending a specially crafted HTML-formatted e-mail message that contains Office ActiveX controls that are used to attempt to exploit this vulnerability.

In a Web-based attack scenario, an attacker would have to host a Web site that contains Office Active X controls that are used to attempt to exploit this vulnerability. In addition, compromised Web sites and Web sites that accept or host user-provided content could contain specially crafted content that could exploit this vulnerability. An attacker would have no way to force users to visit a specially crafted Web site. Instead, an attacker would have to convince them to visit the Web site, typically by getting them to click a link that takes them to the attacker's site.

What systems are primarily at risk from the vulnerability?
Systems where Microsoft Office is used, including workstations and terminal servers, are primarily at risk. 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 on 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 does the update do?
The update addresses the vulnerability by modifying the way memory is accessed by Microsoft Office and by Internet Explorer when loading Access ActiveX controls.

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. This security bulletin addresses the privately disclosed vulnerability as well as additional issues discovered through internal investigations.

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

Other Information
Acknowledgments

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


An anonymous researcher, working with TippingPoint's Zero Day Initiative, for reporting the Access ActiveX Control Vulnerability (CVE-2010-0814)


Robert Freeman of IBM ISS X-Force for reporting the ACCWIZ.dll Uninitialized Variable Vulnerability (CVE-2010-1881)
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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 Security Support or 1-866-PCSAFETY. There is no charge for support calls that are associated with security updates. For more information about available support options, see Microsoft Help and Support.


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.
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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 13, 2010): Bulletin published.

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