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HistoryJul 14, 2009 - 12:00 a.m.

Microsoft Security Bulletin MS09-029 - Critical Vulnerabilities in the Embedded OpenType Font Engine Could Allow Remote Code Execution (961371)

2009-07-1400:00:00
vulners.com
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Microsoft Security Bulletin MS09-029 - Critical
Vulnerabilities in the Embedded OpenType Font Engine Could Allow Remote Code Execution (961371)
Published: July 14, 2009

Version: 1.0
General Information
Executive Summary

This security update resolves two privately reported vulnerabilities in a Microsoft Windows component, the Embedded OpenType (EOT) Font Engine. The vulnerabilities could allow remote code execution. An attacker who successfully exploited either of these vulnerabilities could take complete control of an affected system remotely. 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.

This security update is rated Critical for all supported editions of Microsoft Windows 2000, Windows XP, Windows Server 2003, Windows Vista, and Windows Server 2008. For more information, see the subsection, Affected and Non-Affected Software, in this section.

The update addresses the vulnerability by correcting the way that the Microsoft Windows EOT component parses files and content containing embedded fonts. 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. The majority of customers have automatic updating enabled and will not need to take any action because this security update will be downloaded and installed automatically. Customers who have not enabled automatic updating need to check for updates and install this update manually. For information about specific configuration options in automatic updating, see Microsoft Knowledge Base Article 294871.

For administrators and enterprise installations, or end users who want to install this security update manually, Microsoft recommends that customers apply the update immediately using update management software, or by checking for updates using the Microsoft Update service.

See also the section, Detection and Deployment Tools and Guidance, later in this bulletin.

Known Issues. None
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Affected and Non-Affected Software

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

Affected Software
Operating System Maximum Security Impact Aggregate Severity Rating Bulletins Replaced by this Update

Microsoft Windows 2000 Service Pack 4

Remote Code Execution

Critical

MS06-002

Windows XP Service Pack 2

Remote Code Execution

Critical

MS06-002

Windows XP Service Pack 3

Remote Code Execution

Critical

None

Windows XP Professional x64 Edition Service Pack 2

Remote Code Execution

Critical

None

Windows Server 2003 Service Pack 2

Remote Code Execution

Critical

None

Windows Server 2003 x64 Edition Service Pack 2

Remote Code Execution

Critical

None

Windows Server 2003 with SP2 for Itanium-based Systems

Remote Code Execution

Critical

None

Windows Vista, Windows Vista Service Pack 1, and Windows Vista Service Pack 2

Remote Code Execution

Critical

None

Windows Vista x64 Edition, Windows Vista x64 Edition Service Pack 1, and Windows Vista x64 Edition Service Pack 2

Remote Code Execution

Critical

None

Windows Server 2008 for 32-bit Systems and Windows Server 2008 for 32-bit Systems Service Pack 2*

Remote Code Execution

Critical

None

Windows Server 2008 for x64-based Systems and Windows Server 2008 for x64-based Systems Service Pack 2*

Remote Code Execution

Critical

None

Windows Server 2008 for Itanium-based Systems and Windows Server 2008 for Itanium-based Systems Service Pack 2

Remote Code Execution

Critical

None

*Windows Server 2008 server core installation not affected. The vulnerability addressed by this update does not affect supported editions of Windows Server 2008 if Windows Server 2008 was installed using the Server Core installation option. For more information on this installation option, see Server Core. Note that the Server Core installation option does not apply to certain editions of Windows Server 2008; see Compare Server Core Installation Options.
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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.

Is the Windows 7 Beta release affected by this vulnerability?
Yes. These vulnerabilities were reported after the release of Windows 7 Beta. Customers running this platform are encouraged to download and apply the update to their systems

Security updates are available from Microsoft Update and Windows 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. 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.
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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 Embedded OpenType Font Heap Overflow Vulnerability - CVE-2009-0231 Embedded OpenType Font Integer Overflow Vulnerability - CVE-2009-0232 Aggregate Severity Rating

Microsoft Windows 2000 Service Pack 4

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical

Windows XP Service Pack 2

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical

Windows XP Service Pack 3

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical

Windows XP Professional x64 Edition Service Pack 2

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical

Windows Server 2003 Service Pack 2

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical

Windows Server 2003 x64 Edition Service Pack 2

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical

Windows Server 2003 with SP2 for Itanium-based Systems

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical

Windows Vista, Windows Vista Service Pack 1, and Windows Vista Service Pack 2

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical

Windows Vista x64 Edition, Windows Vista x64 Edition Service Pack 1, and Windows Vista x64 Edition Service Pack 2

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical

Windows Server 2008 for 32-bit Systems and Windows Server 2008 for 32-bit Systems Service Pack 2*

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical

Windows Server 2008 for x64-based Systems and Windows Server 2008 for x64-based Systems Service Pack 2*

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical

Windows Server 2008 for Itanium-based Systems and Windows Server 2008 for Itanium-based Systems Service Pack 2

Critical
Remote Code Execution

Critical
Remote Code Execution

Critical

*Windows Server 2008 server core installation not affected. The vulnerability addressed by this update does not affect supported editions of Windows Server 2008 if Windows Server 2008 was installed using the Server Core installation option. For more information on this installation option, see Server Core. Note that the Server Core installation option does not apply to certain editions of Windows Server 2008; see Compare Server Core Installation Options.
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Embedded OpenType Font Heap Overflow Vulnerability - CVE-2009-0231

A remote code execution vulnerability exists in the way that Microsoft Windows Embedded OpenType (EOT) font technology parses data records in specially crafted embedded fonts. If a user is logged on with administrative user rights, 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.

To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2009-0231.

Mitigating Factors for Embedded OpenType Font Heap Overflow Vulnerability - CVE-2009-0231

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.
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Workarounds for Embedded OpenType Font Heap Overflow Vulnerability - CVE-2009-0231

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:

Disable support for parsing embedded fonts in Internet Explorer

Disabling the support for the parsing of embedded fonts in Internet Explorer prevents this application from being used as an attack vector. However, additional attack vectors, such as embedded fonts within a Microsoft Office document, could still be exploited.

Using the Interactive Method

In Internet Explorer, click Internet Options on the Tools menu

Click the Security tab

Click Internet, and then click Custom Level

Scroll down to the Downloads section and select Prompt or Disable for the Font Downloading security setting

Click OK two times to return to Internet Explorer

Using Group Policy

Note The Group Policy MMC snap-in can be used to set policy for a machine, for an organizational unit or an entire domain. 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

Perform the following steps:

Open the Group Policy Management Console and configure it to work with the appropriate Group Policy object (e.g., local machine, OU or domain GPO).

Navigate to the following node:

User Configuration - Windows Settings - Internet Explorer - Maintenance - Security

Double-click Security Zones and Content Rating.

In the Security Zones and Content Rating dialog box, select Import the current security zones and privacy settings and then click the Modify Settings button.

Note This will create a Group Policy for Internet Explorer based on the settings of the currently logged-on user.

In the Internet Properties dialog box, ensure the Internet zone is selected and then press Custom Level.

Scroll down to Downloads and set Font Download to Prompt or Disable.

Press OK to return to the Internet Properties dialog box.

Repeat these steps for the Local Intranet zone.

Press OK three times to return to the Group Policy Management Console.

Refresh the Group Policy on all machines or wait for the next scheduled Group Policy refresh interval for the settings to take effect.

Using a Managed Deployment Script

This security setting can be manually entered into the registry by creating a registry script and importing it either by double-clicking it or running regedit.exe as part of a logon or machine startup script. For managed deployments Regedit.exe can be used to import a registry script silently with the '-s' switch. For more information on regedit command line switches, see Microsoft Knowledge Base Article 82821, "Registration Info Editor (REGEDIT) Command-Line Switches."

To set this setting to 'Prompt' for the Internet and Local Intranet Zones paste the following text into a .REG file and then import the .REG file on managed machines as part of your organization's managed deployment process:

Windows Registry Editor Version 5.00

; Zone 1 is the local intranet zone
; 1604 is the Font download policy
; dword:00000001 sets the policy to prompt
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\1]
"1604"=dword:00000001
; Zone 3 is the internet zone
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3]
"1604"=dword:00000001

To set this setting to 'Disable' for the Internet and Local Intranet Zones paste the following text into a .REG file and then import the .REG file on managed machines as part of your organization's managed deployment process:

Windows Registry Editor Version 5.00

; Zone 1 is the local intranet zone
; 1604 is the Font download policy
; dword:00000003 sets the policy to disable
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\1]
"1604"=dword:00000003
; Zone 3 is the internet zone
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3]
"1604"=dword:00000003

Impact of workaround. Web sites making use of embedded font technology will fail to display properly.

Deny Access to T2EMBED.DLL

On Windows 2000, Windows XP, and Windows Server 2003:

For 32-bit systems, enter the following command at an administrative command prompt:

Echo y| cacls "%windir%\system32\t2embed.dll" /E /P everyone:N

For 64-bit systems, enter the following command from an administrative command prompt:

Echo y| cacls "%windir%\syswow64\t2embed.dll" /E /P everyone:N

On Windows Vista and Windows Server 2008:

For 32-bit systems, enter the following command at an administrative command prompt:

Takeown.exe /f "%windir%\system32\t2embed.dll"
Icacls.exe "%windir%\system32\t2embed.dll" /save %TEMP%\t2embed_ACL.TXT
Icacls.exe "%windir%\system32\t2embed.dll" /deny everyone:(F)

For 64-bit systems, enter the following command at an administrative command prompt:

Takeown.exe /f "%windir%\syswow64\t2embed.dll"
Icacls.exe "%windir%\syswow64\t2embed.dll" /save %TEMP%\t2embed_ACL.TXT
Icacls.exe "%windir%\syswow64\t2embed.dll" /deny everyone:(F)

Impact of workaround. Applications that rely on embedded font technology will fail to display properly.

How to undo the workaround.

On Windows 2000, Windows XP, and Windows Server 2003:

For 32-bit systems, enter the following command at an administrative command prompt:

cacls "%windir%\system32\t2embed.dll" /E /R everyone

For 64-bit systems, enter the following command at an administrative command prompt:

cacls "%windir%\syswow64\t2embed.dll" /E /R everyone

On Windows Vista and Windows Server 2008:

For 32-bit systems, enter the following command at an administrative command prompt:

Icacls.exe "%windir%\system32" /restore %TEMP%\t2embed_ACL.TXT

For 64-bit systems, enter the following command at an administrative command prompt:

Icacls.exe "%windir%\syswow64" /restore %TEMP%\t2embed_ACL.TXT

Note Microsoft is providing a capability to implement this workaround automatically. For more information on the use of this tool, see Microsoft Knowledge Base Article 961371.

Important Enabling this workaround via the "Enable workaround Fix it" package above will prevent the security update for this issue from installing successfully. The "Disable workaround Fix it" must be applied to the system prior to installing the security update for this issue.
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FAQ for Embedded OpenType Font Heap Overflow Vulnerability - CVE-2009-0231

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 remotely. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

What causes the vulnerability?
The vulnerability is caused by a buffer overflow when a Microsoft Windows component, the Embeded OpenType Font Engine, parses name tables within specially crafted files and content containing embedded fonts.

What are Embedded OpenType (EOT) Fonts?
Embedded OpenType (EOT) fonts are a compact form of fonts designed for use on Web pages. These fonts can be embedded in a document. Use of EOT fonts ensures that a user views the document exactly as the author intended. The Web Embedding Fonts Tool (WEFT) lets Web authors create font objects that are linked to their Web pages so that when viewed through the browser, pages display in the style contained in the font object. For more information, see MSDN article, About Font Embedding. All platforms listed in the Affected Software table support the rendering of EOT fonts by default.

What might an attacker use the vulnerability to do?
An attacker who successfully exploited this vulnerability could take complete control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

How could an attacker exploit the vulnerability?
This vulnerability requires that a user view content rendered in a specially crafted EOT font.

In an e-mail attack scenario, an attacker could exploit the vulnerability by sending an e-mail message with a Microsoft Word or PowerPoint file containing a specially crafted EOT font embedded in the document and convincing the user to open or preview the file.

In a Web-based attack scenario, an attacker would have to host a Web site that contains specially crafted embedded fonts 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 them to the attacker's site.

What systems are primarily at risk from the vulnerability?
Workstations and terminal servers are primarily at risk. Servers could be at more risk if users who should not have sufficient administrative permissions are given the ability to log on to servers and to run programs. However, best practices strongly discourage allowing this.

What does the update do?
The update addresses the issue by correcting the way that the Embedded OpenType Font Engine parses files and content containing embedded fonts.

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

When this security bulletin was issued, had Microsoft received any reports that this vulnerability was being exploited?
No. Microsoft had not received any information to indicate that this vulnerability had been publicly used to attack customers and had not seen any examples of proof of concept code published when this security bulletin was originally issued.
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Embedded OpenType Font Integer Overflow Vulnerability - CVE-2009-0232

A remote code execution vulnerability exists in the way that Microsoft Windows Embedded OpenType (EOT) font technology parses name tables in specially crafted embedded fonts. If a user is logged on with administrative user rights, 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.

To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2009-0232.

Mitigating Factors for Embedded OpenType Font Integer Overflow Vulnerability - CVE-2009-0232

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.
Top of sectionTop of section

Workarounds for Embedded OpenType Font Integer Overflow Vulnerability - CVE-2009-0232

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:

Disable support for parsing embedded fonts in Internet Explorer

Disabling the support for the parsing of embedded fonts in Internet Explorer prevents this application from being used as an attack vector. However, additional attack vectors, such as embedded fonts within a Microsoft Office document, could still succeed.

Using the Interactive Method

In Internet Explorer, click Internet Options on the Tools menu

Click the Security tab

Click Internet, and then click Custom Level

Scroll down to the Downloads section and select Prompt or Disable for the Font Downloading security setting

Click OK two times to return to Internet Explorer

Using Group Policy

Note The Group Policy MMC snap-in can be used to set policy for a machine, for an organizational unit or an entire domain. 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

Perform the following steps:

Open the group policy management console and configure it to work with the appropriate group policy object (e.g., local machine, OU or domain GPO).

Navigate to the following node:

User Configuration - Windows Settings - Internet Explorer - Maintenance - Security

Double-click Security Zones and Content Rating.

In the Security Zones and Content Rating dialog box, select Import the current security zones and privacy settings and then click the Modify Settings button.

Note This will create a group policy for Internet Explorer based on the settings of the currently logged-on user.

In the Internet Properties dialog box, ensure the Internet zone is selected and then press Custom Level.

Scroll down to Downloads and set Font Download to Prompt or Disable.

Press OK to return to the Internet Properties dialog box.

Repeat these steps for the Local Intranet zone.

Press OK three times to return to the group policy management console.

Refresh the group policy on all machines or wait for the next scheduled group policy refresh interval for the settings to take effect.

Using a Managed Deployment Script

This security setting can be manually entered into the registry by creating a registry script and importing it either by double-clicking it or running regedit.exe as part of a logon or machine startup script. For managed deployments Regedit.exe can be used to import a registry script silently with the '-s' switch. For more information on regedit command line switches, see Microsoft Knowledge Base Article 82821, "Registration Info Editor (REGEDIT) Command-Line Switches."

To set this setting to 'Prompt' for the Internet and Local Intranet Zones paste the following text into a .REG file and then import the .REG file on managed machines as part of your organization's managed deployment process:

Windows Registry Editor Version 5.00

; Zone 1 is the local intranet zone
; 1604 is the Font download policy
; dword:00000001 sets the policy to prompt
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\1]
"1604"=dword:00000001
; Zone 3 is the internet zone
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3]
"1604"=dword:00000001

To set this setting to 'Disable' for the Internet and Local Intranet Zones paste the following text into a .REG file and then import the .REG file on managed machines as part of your organization's managed deployment process:

Windows Registry Editor Version 5.00

; Zone 1 is the local intranet zone
; 1604 is the Font download policy
; dword:00000003 sets the policy to disable
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\1]
"1604"=dword:00000003
; Zone 3 is the internet zone
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3]
"1604"=dword:00000003

Impact of workaround. Web sites making use of embedded font technology will fail to display properly.

Deny Access to T2EMBED.DLL

On Windows 2000, Windows XP, and Windows Server 2003:

For 32-bit systems, enter the following command at an administrative command prompt:

Echo y| cacls "%windir%\system32\t2embed.dll" /E /P everyone:N

For 64-bit systems, enter the following command from an administrative command prompt:

Echo y| cacls "%windir%\syswow64\t2embed.dll" /E /P everyone:N

On Windows Vista and Windows Server 2008:

For 32-bit systems, enter the following command at an administrative command prompt:

Takeown.exe /f "%windir%\system32\t2embed.dll"
Icacls.exe "%windir%\system32\t2embed.dll" /save %TEMP%\t2embed_ACL.TXT
Icacls.exe "%windir%\system32\t2embed.dll" /deny everyone:(F)

For 64-bit systems, enter the following command at an administrative command prompt:

Takeown.exe /f "%windir%\syswow64\t2embed.dll"
Icacls.exe "%windir%\syswow64\t2embed.dll" /save %TEMP%\t2embed_ACL.TXT
Icacls.exe "%windir%\syswow64\t2embed.dll" /deny everyone:(F)

Impact of workaround. Applications that rely on embedded font technology will fail to display properly.

How to undo the workaround.

On Windows 2000, Windows XP, and Windows Server 2003:

For 32-bit systems, enter the following command at an administrative command prompt:

cacls "%windir%\system32\t2embed.dll" /E /R everyone

For 64-bit systems, enter the following command at an administrative command prompt:

cacls "%windir%\syswow64\t2embed.dll" /E /R everyone

On Windows Vista and Windows Server 2008:

For 32-bit systems, enter the following command at an administrative command prompt:

Icacls.exe "%windir%\system32" /restore %TEMP%\t2embed_ACL.TXT

For 64-bit systems, enter the following command at an administrative command prompt:

Icacls.exe "%windir%\syswow64" /restore %TEMP%\t2embed_ACL.TXT

Note Microsoft is providing a capability to implement this workaround automatically. For more information on the use of this tool, see Microsoft Knowledge Base Article 961371.

Important Enabling this workaround via the "Enable workaround Fix it" package above will prevent the security update for this issue from installing successfully. The "Disable workaround Fix it" must be applied to the system prior to installing the security update for this issue.
Top of sectionTop of section

FAQ for Embedded OpenType Font Integer Overflow Vulnerability - CVE-2009-0232

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 remotely. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

What causes the vulnerability?
The vulnerability is caused by an integer overflow when a Microsoft Windows component, the Embeded OpenType Font Engine, parses name tables within specially crafted files and content containing embedded fonts.

What are Embedded OpenType (EOT) Fonts?
Embedded OpenType (EOT) fonts are a compact form of fonts designed for use on Web pages. These fonts can be embedded in a document. This ensures that a user views the document exactly as the author intended. The Web Embedding Fonts Tool (WEFT) lets Web authors create font objects that are linked to their Web pages so that when viewed through the browser, pages display in the style contained in the font object. For more information, see the MSDN article, About Font Embedding. All platforms listed in the Affected Software table support the rendering of EOT fonts by default.

What might an attacker use the vulnerability to do?
An attacker who successfully exploited this vulnerability could take complete control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

How could an attacker exploit the vulnerability?
This vulnerability requires that a user view content rendered in a specially crafted EOT font.

In an e-mail attack scenario, an attacker could exploit the vulnerability by sending an e-mail message with a Microsoft Word or PowerPoint file containing a specially crafted EOT font attached and convincing the user to open or preview the file.

In a Web-based attack scenario, an attacker would have to host a Web site that contains specially crafted content that is 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 them to the attacker's site.

What systems are primarily at risk from the vulnerability?
Workstations and terminal servers are primarily at risk. Servers could be at more risk if users who should not have sufficient administrative permissions are given the ability to log on to servers and to run programs. However, best practices strongly discourage allowing this.

What does the update do?
The update addresses the issue by correcting the way that the Embedded OpenType Font Engine parses files and content containing embedded fonts.

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

When this security bulletin was issued, had Microsoft received any reports that this vulnerability was being exploited?
No. Microsoft had not received any information to indicate that this vulnerability had been publicly used to attack customers 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:

VeriSign iDefense Labs for reporting the Embedded OpenType Font Heap Overflow Vulnerability (CVE-2009-0231)

Thomas Garnier for reporting the Embedded OpenType Font Integer Overflow Vulnerability (CVE-2009-0232)
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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.
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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.

Disclaimer

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Revisions

V1.0 (July 14, 2009): Bulletin published.

Related for SECURITYVULNS:DOC:22163