SecurityvulnsSECURITYVULNS:DOC:21651Microsoft Security Bulletin MS09-010 - Critical Vulnerabilities in WordPad and Office Text Converters Could Allow Remote Code Execution (960477)
Microsoft Security Bulletin MS09-010 - Critical
Vulnerabilities in WordPad and Office Text Converters Could Allow Remote Code Execution (960477)
Published: April 14, 2009
Version: 1.0
General Information
Executive Summary
This security update resolves two publicly disclosed vulnerabilities and two privately reported vulnerabilities in Microsoft WordPad and Microsoft Office text converters. The vulnerabilities could allow remote code execution if a specially crafted file is opened in WordPad or Microsoft Office Word. Do not open Microsoft Office, RTF, Write, or WordPerfect files from untrusted sources using affected versions of WordPad or Microsoft Office Word.
This security update is rated Critical for supported editions of Microsoft Office Word 2000. This security update is also rated Important for supported editions of Microsoft Office Word 2002; Microsoft Office Converter Pack; and WordPad on all supported editions of Microsoft Windows 2000, Windows XP, and Windows Server 2003. For more information, see the subsection, Affected and Non-Affected Software, in this section.
This security update addresses the vulnerabilities by modifying the way that Microsoft Office Word and Office text converters handle opening specially crafted Word 6.0, Windows Write, and WordPerfect documents. This security update also addresses the vulnerabilities by implementing fixes to WordPad and by preventing WordPad on affected platforms from opening Word 6.0 and Windows Write files. For more information about the vulnerabilities, see the Frequently Asked Questions (FAQ) subsection for the specific vulnerability entry under the next section, Vulnerability Information.
This security update also addresses the vulnerability first described in Microsoft Security Advisory 960906.
Recommendation. Microsoft recommends that customers apply the update immediately.
Known Issues. Microsoft Knowledge Base Article 960477 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
Windows Operating System and Components
Operating System Component Maximum Security Impact Aggregate Severity Rating Bulletins Replaced by this Update
Microsoft Windows 2000 Service Pack 4
Not applicable
Remote Code Execution
Important
None
Windows XP Service Pack 2 and Windows XP Service Pack 3
Not applicable
Remote Code Execution
Important
None
Windows XP Professional x64 Edition and Windows XP Professional x64 Edition Service Pack 2
Not applicable
Remote Code Execution
Important
None
Windows Server 2003 Service Pack 1 and Windows Server 2003 Service Pack 2
Not applicable
Remote Code Execution
Important
None
Windows Server 2003 x64 Edition and Windows Server 2003 x64 Edition Service Pack 2
Not applicable
Remote Code Execution
Important
None
Windows Server 2003 with SP1 for Itanium-based Systems and Windows Server 2003 with SP2 for Itanium-based Systems
Not applicable
Remote Code Execution
Important
None
Microsoft Office
Office Suite and Other Software Component Maximum Security Impact Aggregate Severity Rating Bulletins Replaced by this Update
Microsoft Office Suites and Components
Microsoft Office 2000 Service Pack 3
Microsoft Office Word 2000 Service Pack 3
(KB921606)
Remote Code Execution
Critical
MS04-027
Microsoft Office XP Service Pack 3
Microsoft Office Word 2002 Service Pack 3
(KB933399)
Remote Code Execution
Important
MS04-027
Other Office Software
Microsoft Office Converter Pack
(KB960476)
Not applicable
Remote Code Execution
Important
None
Non-Affected Software
Windows Operating System
Windows Vista and Windows Vista Service Pack 1
Windows Vista x64 Edition and Windows Vista x64 Edition Service Pack 1
Windows Server 2008 for 32-bit Systems*
Windows Server 2008 for x64-based Systems*
Windows Server 2008 for Itanium-based Systems
Office and Other Software
Microsoft Office Word 2003 Service Pack 3
Microsoft Office Word 2007 Service Pack 1
Microsoft Office Word Viewer 2003 Service Pack 3
Microsoft Office Word Viewer
Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats
Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats Service Pack 1
Microsoft Office 2004 for Mac
Microsoft Office 2008 for Mac
Open XML File Format Converter for Mac
Microsoft Works 8.0
Microsoft Works 8.5
Microsoft Works 9.0
Microsoft Works Suite 2006
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 960477.
What are the known issues that customers may experience when installing this security update?
Microsoft Knowledge Base Article 960477 documents the currently known issues that customers may experience when they install this security update. The article also documents recommended solutions for these issues.
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.
Does this update contain any security-related changes to functionality?
Yes, in addition to implementing solutions for the security vulnerabilities, this security update also addresses the vulnerabilities by preventing WordPad on affected platforms from opening Word 6.0 and Write files. When WordPad attempts to open a Word 6.0 or Write file, the file will not open and a dialog box will be displayed. For more information, see Microsoft Knowledge Base Article 960477.
Does this update contain any additional changes to the converters?
In addition to addressing the vulnerabilities described in this bulletin, this update also replaces RTF, HTML and Word 97 text converters used by WordPad and Microsoft Office. These text converters are being replaced to resolve additional issues identified during the investigation of the vulnerabilities described in this security bulletin.
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
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 April bulletin summary. For more information, see Microsoft Exploitability Index.
Vulnerability Severity Rating and Maximum Security Impact by Affected Software
Affected Software WordPad and Office Text Converter Memory Corruption Vulnerability - CVE-2009-0087 WordPad Word 97 Text Converter Stack Overflow Vulnerability - CVE-2008-4841 Word 2000 WordPerfect 6.x Converter Stack Corruption Vulnerability - CVE-2009-0088 WordPad Word 97 Text Converter Stack Overflow Vulnerability - CVE-2009-0235 Aggregate Severity Rating
Operating System and Components
Microsoft Windows 2000 Service Pack 4
Important
Remote Code Execution
Important
Remote Code Execution
Not applicable
Important
Remote Code Execution
Important
Windows XP Service Pack 2
Moderate
Remote Code Execution
Important
Remote Code Execution
Not applicable
Important
Remote Code Execution
Important
Windows XP Service Pack 3
Moderate
Remote Code Execution
Not applicable
Not applicable
Important
Remote Code Execution
Important
Windows XP Professional x64 Edition and Windows XP Professional x64 Edition Service Pack 2
Moderate
Remote Code Execution
Important
Remote Code Execution
Not applicable
Important
Remote Code Execution
Important
Windows Server 2003 Service Pack 1 and Windows Server 2003 Service Pack 2
Moderate
Remote Code Execution
Important
Remote Code Execution
Not applicable
Important
Remote Code Execution
Important
Windows Server 2003 x64 Edition and Windows Server 2003 x64 Edition Service Pack 2
Moderate
Remote Code Execution
Important
Remote Code Execution
Not applicable
Important
Remote Code Execution
Important
Windows Server 2003 with SP1 for Itanium-based Systems and Windows Server 2003 with SP2 for Itanium-based Systems
Moderate
Remote Code Execution
Important
Remote Code Execution
Not applicable
Important
Remote Code Execution
Important
Office Software and Components
Microsoft Office Word 2000 Service Pack 3
Critical
Remote Code Execution
Not applicable
Critical
Remote Code Execution
Not applicable
Critical
Microsoft Office Word 2002 Service Pack 3
Important
Remote Code Execution
Not applicable
Not applicable
Not applicable
Important
Microsoft Office Converter Pack
Not applicable
Not applicable
Important
Remote Code Execution
Not applicable
Important
Top of sectionTop of section
WordPad and Office Text Converter Memory Corruption Vulnerability - CVE-2009-0087
A remote code execution vulnerability exists in the way that text converters in WordPad and Microsoft Office process memory when a user opens a specially crafted Word 6 file that includes malformed data.
To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2009-0087.
Mitigating Factors for WordPad and Office Text Converter Memory Corruption Vulnerability - CVE-2009-0087
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 would have to host a Web site that contains a Web page that is used to exploit this vulnerability. An attacker would have no way to force users to visit a malicious 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. After they click the link, they would be prompted to perform several actions. An attack could only occur after they performed these actions.
•
The vulnerability could not be exploited automatically through e-mail. For an attack to be successful a user must open an attachment that is sent in an e-mail message.
•
An attacker who successfully exploited this vulnerability could gain the same privileges as the user. Users whose accounts are configured to have fewer privileges on the system could be less impacted than users who operate with administrative privileges.
•
All supported editions of Windows XP and Windows Server 2003 are at a reduced risk to this vulnerability because the affected component is disabled by default. These operating systems are only vulnerable if an administrator has manually enabled the affected component. All supported editions of Windows Vista and Windows Server 2008 do not contain the affected component and are also unaffected.
Microsoft Windows 2000 Service Pack 4 systems are more at risk because the converter is still active in a default installation. However, on Microsoft Windows 2000 Service Pack 4 systems that have applied the MS04-041 update, the Word for Windows 6.0 converter will be disabled by default.
•
Users who have installed and are using the Office Document Open Confirmation Tool for Office 2000 will be prompted with Open, Save, or Cancelbefore opening a document. The features of the Office Document Open Confirmation Tool are incorporated in Office XP and later editions of Office.
Top of sectionTop of section
Workarounds for WordPad and Office Text Converter Memory Corruption Vulnerability - CVE-2009-0087
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 or save Microsoft Office files that you receive from untrusted sources or that you receive unexpectedly from trusted sources with affected versions of WordPad or Microsoft Office.
Do not open Office, RTF or Write files from untrusted sources using any software listed as affected in this bulletin on systems that are not updated with the security updates that accompany this bulletin. This vulnerability could be exploited when a user opens a specially crafted file.
This includes files that have .wri, .rtf, and .doc file associations. WordPad and Office could also be used to manually open documents. This includes all files that have .wri, .rtf, and .doc file extensions as well files with other extensions. Be aware that WordPad could also be used to open specially crafted documents regardless of the file name extension.
•
Disable the Word 6 converter by restricting access
An administrator can apply an access control list to affected converters to ensure that the converter is no longer loaded by WordPad and Office. This effectively prevents exploitation of the issue using this attack vector.
In order to apply the access list, run the following commands from the command prompt. Note that some of these may result in an error message, this is expected.
echo y| cacls "%ProgramFiles%\Windows NT\Accessories\mswrd6.wpc" /E /P everyone:N
echo y| cacls "%ProgramFiles%\Common Files\Microsoft Shared\TextConv\mswrd632.wpc" /E /P everyone:N
echo y| cacls "%ProgramFiles%\Common Files\Microsoft Shared\TextConv\mswrd632.cnv" /E /P everyone:N
echo y| cacls "%ProgramFiles(x86)%\Common Files\Microsoft Shared\TextConv\mswrd632.wpc" /E /P everyone:N
echo y| cacls "%ProgramFiles(x86)%\Common Files\Microsoft Shared\TextConv\mswrd632.cnv" /E /P everyone:N
echo y| cacls "%ProgramFiles%\Windows NT\Accessories\mswrd664.wpc" /E /P everyone:N
echo y| cacls "%ProgramFiles(x86)%\Windows NT\Accessories\mswrd6.wpc" /E /P everyone:N
Impact of workaround. Upon implementing the workaround, the user will no longer be able to convert Word 6 documents to WordPad RTF or Word 2003 documents. Microsoft Office Word will return an error saying, "The file appears to be corrupted."
How to undo the workaround.
echo y| cacls "%ProgramFiles%\Windows NT\Accessories\mswrd6.wpc" /E /R everyone
echo y| cacls "%ProgramFiles%\Common Files\Microsoft Shared\TextConv\mswrd632.wpc" /E /R everyone
echo y| cacls "%ProgramFiles%\Common Files\Microsoft Shared\TextConv\mswrd632.cnv" /E /R everyone
echo y| cacls "%ProgramFiles(x86)%\Common Files\Microsoft Shared\TextConv\mswrd632.wpc" /E /R everyone
echo y| cacls "%ProgramFiles(x86)%\Common Files\Microsoft Shared\TextConv\mswrd632.cnv" /E /R everyone
echo y| cacls "%ProgramFiles%\Windows NT\Accessories\mswrd664.wpc" /E /R everyone
echo y| cacls "%ProgramFiles(x86)%\Windows NT\Accessories\mswrd6.wpc" /E /R everyone
Top of sectionTop of section
FAQ for WordPad and Office Text Converter Memory Corruption Vulnerability - CVE-2009-0087
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 or view, change, or delete data; or create new accounts with full user rights.
What causes the vulnerability?
A vulnerability exists in WordPad and Office text converters that allows an attacker to execute remote code when a user opens a specially crafted attacker-supplied document. The specific vulnerability exists in the way that the Word 6 converter parses the specially crafted document.
What are WordPad Text Converters and Office Text Converters?
WordPad is a default component of Microsoft Windows operating systems. Text converters in WordPad allow users who do not have Microsoft Office Word installed to open documents in Microsoft Windows Write (.wri) and Microsoft Office Word 6.0, Microsoft Office Word 97, Microsoft Office Word 2000, and Microsoft Office Word 2002 (.doc) file formats. These text converters also allow users to save documents in the Word 6.0 file format.
Text converters are also a default component of Microsoft Office that allow users to open and save as older Office file formats, including the Word 6.0 file format.
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 a user open a specially crafted document with an affected version of WordPad or Microsoft Office Word.
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 using either WordPad or Microsoft Office.
In a Web-based attack scenario, an attacker would have to host a Web site that contains a document 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 that takes them to the attacker's site.
How are supported editions of Microsoft Windows 2000, Windows XP, and Windows Server 2003 affected by this vulnerability?
The Word for Windows 6.0 converter is not enabled by default on systems running supported editions of Windows XP and Windows Server 2003. However, if the Word for Windows 6.0 converter has been manually enabled, such as per the instructions in Microsoft Knowledge Base Article 870883, the system will be at risk of this vulnerability. See the workaround, Disable the Word 6 converter by restricting access, for details on disabling the Word for Windows 6.0 converter if it has been enabled.
On Microsoft Windows 2000 Service Pack 4 systems, the bulletin is rated with severity of Important because the converter is still active in a default installation. However, on Microsoft Windows 2000 Service Pack 4 systems that have applied the MS04-041 update, the Word for Windows 6.0 converter will be disabled by default.
What systems are primarily at risk from the vulnerability?
All systems with WordPad or Microsoft Office Word where Word documents are opened from untrusted sources 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.
What does the update do?
This update removes the vulnerability by disabling the WordPad Word 6 and Windows Write text converters.
When this security bulletin was issued, had this vulnerability been publicly disclosed?
Yes. This vulnerability has been publicly disclosed. It has been assigned Common Vulnerability and Exposure number CVE-2009-0087.
When this security bulletin was issued, had Microsoft received any reports that this vulnerability was being exploited?
Exploit code is publicly available of a variant of this issue that may cause a Denial of Service condition in WordPad. Microsoft is not currently aware of publicly available exploit code of this issue that leads to remote code execution.
Does applying this security update help protect customers from the code, published publicly, that attempts to exploit this vulnerability?
Yes. This security update addresses the vulnerability that is currently being exploited.
Top of sectionTop of section
Top of sectionTop of section
WordPad Word 97 Text Converter Stack Overflow Vulnerability - CVE-2008-4841
A remote code execution vulnerability exists in the way that Microsoft WordPad processes memory when parsing a specially crafted Word 97 document. The vulnerability could allow remote code execution if a user opens a specially crafted Word file that includes a malformed list structure.
To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2008-4841.
Mitigating Factors for WordPad Word 97 Text Converter Stack Overflow Vulnerability - CVE-2008-4841
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 would have to host a Web site that contains a Web page that is used to exploit this vulnerability. An attacker would have no way to force users to visit a malicious 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. After they click the link, they would be prompted to perform several actions. An attack could only occur after they performed these actions.
•
The vulnerability could not be exploited automatically through e-mail. For an attack to be successful a user must open an attachment that is sent in an e-mail message.
•
An attacker who successfully exploited this vulnerability could gain the same privileges as the user. Users whose accounts are configured to have fewer privileges on the system could be less impacted than users who operate with administrative privileges.
•
A website attempting to exploit the vulnerability would cause a dialog box to appear. The user would be prompted to decide if they wanted to open the file or not, unless the user had previously unchecked the option "Always ask before opening this type of file."
Top of sectionTop of section
Workarounds for WordPad Word 97 Text Converter Stack Overflow Vulnerability - CVE-2008-4841
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 or save Microsoft Office, RTF or Write 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.
This includes all files that have .wri, .rtf, and .doc file extensions as well files with other extensions. Be aware that WordPad could also be used to open specially crafted documents regardless of the file name extension.
•
Disable the Word 6 converter by restricting access to mswrd8.wpc
An administrator can apply an access control list to the affected converter to ensure it is no longer loaded by WordPad. This effectively prevents exploitation of the issue.
In order to apply the access control list, run the following commands from the command prompt. Note that some of these commands may result in an error message. This error message is expected.
echo y| cacls "%ProgramFiles%\Common Files\Microsoft Shared\TextConv\mswrd832.cnv" /E /P everyone:N
echo y| cacls "%ProgramFiles(x86)%\Common Files\Microsoft Shared\TextConv\mswrd832.cnv" /E /P everyone:N
echo y| cacls "%ProgramFiles%\Windows NT\Accessories\mswrd8.wpc" /E /P everyone:N
echo y| cacls "%ProgramFiles%\Windows NT\Accessories\mswrd864.wpc" /E /P everyone:N
echo y| cacls "%ProgramFiles(x86)%\Windows NT\Accessories\mswrd8.wpc" /E /P everyone:N
Impact of workaround. WordPad will no longer load Word 97 (Word 6.0) documents.
How to undo the workaround.
echo y| cacls "%ProgramFiles%\Common Files\Microsoft Shared\TextConv\mswrd832.cnv" /E /R everyone
echo y| cacls "%ProgramFiles(x86)%\Common Files\Microsoft Shared\TextConv\mswrd832.cnv" /E /R everyone
echo y| cacls "%ProgramFiles%\Windows NT\Accessories\mswrd8.wpc" /E /R everyone
echo y| cacls "%ProgramFiles%\Windows NT\Accessories\mswrd864.wpc" /E /R everyone
echo y| cacls "%ProgramFiles(x86)%\Windows NT\Accessories\mswrd8.wpc" /E /R everyone
Top of sectionTop of section
FAQ for WordPad Word 97 Text Converter Stack Overflow Vulnerability - CVE-2008-4841
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 or view, change, or delete data; or create new accounts with full user rights.
What causes the vulnerability?
This vulnerability requires that a user open a specially crafted Word 97 document with an affected version of WordPad.
What are WordPad Text Converters?
WordPad is a default component of Microsoft Windows operating systems. Text converters in WordPad allow users who do not have Microsoft Office Word installed to open documents in Microsoft Windows Write (.wri) and Microsoft Office Word 6.0, Microsoft Office Word 97, Microsoft Office Word 2000, and Microsoft Office Word 2002 (.doc) file formats. These text converters also allow users to save documents in the Word 6.0 file format.
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?
In an e-mail attack scenario, an attacker could exploit the vulnerability by sending a specially crafted Word 97 file to the user and by convincing the user to open the file.
In a Web-based attack scenario, an attacker would have to host a Web site that contains a Word 97 document 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 that takes them to the attacker's web site.
What systems are primarily at risk from the vulnerability?
All systems where WordPad is used to open Word documents from untrusted sources, such as workstations or 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.
What does the update do?
This update removes the vulnerability by changing the way that the WordPad Text Converters handle opening specially crafted Word 97 files.
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-2008-4841. This vulnerability was first described in Microsoft Security Advisory 960906.
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.
Top of sectionTop of section
Top of sectionTop of section
Word 2000 WordPerfect 6.x Converter Stack Corruption Vulnerability - CVE-2009-0088
A remote code execution vulnerability exists in the way that the WordPerfect 6.x converter that is included with Microsoft Office Word 2000 processes memory when parsing a specially crafted WordPerfect document.
To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2009-0088.
Mitigating Factors for Word 2000 WordPerfect 6.x Converter Stack Corruption Vulnerability - CVE-2009-0088
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. After they click the link, they would be prompted to perform several actions. An attack could only occur after they performed these actions.
•
The vulnerability could not be exploited automatically through e-mail. For an attack to be successful a user must open an attachment that is sent in an e-mail message.
•
An attacker who successfully exploited this vulnerability could gain the same privileges as the user. Users whose accounts are configured to have fewer privileges on the system could be less impacted than users who operate with administrative privileges.
•
Users who have installed and are using the Office Document Open Confirmation Tool for Office 2000 will be prompted with Open, Save, or Cancelbefore opening a document. The features of the Office Document Open Confirmation Tool are incorporated in Office XP and later editions of Office.
Top of sectionTop of section
Workarounds for Word 2000 WordPerfect 6.x Converter Stack Corruption Vulnerability - CVE-2009-0088
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 or save 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.
•
Disable the Office text converter by restricting access to wpft632.cnv
An administrator can apply an access list to the affected converter to ensure it is no longer loaded by Microsoft Office Word. This effectively prevents exploitation of the issue.
In order to apply the access list, run the following command from the command prompt.
echo y| cacls "%ProgramFiles%\Common Files\Microsoft Shared\TextConv\wpft632.cnv" /E /P everyone:N
echo y| cacls "%ProgramFiles(x86)%\Common Files\Microsoft Shared\TextConv\wpft632.cnv" /E /P everyone:N
Impact of workaround. Microsoft Office Word will no longer load WordPerfect documents.
How to undo the workaround.
echo y| cacls "%ProgramFiles%\Common Files\Microsoft Shared\TextConv\wpft632.cnv" /E /R everyone
echo y| cacls "%ProgramFiles(x86)%\Common Files\Microsoft Shared\TextConv\wpft632.cnv" /E /R everyone
Top of sectionTop of section
FAQ for Word 2000 WordPerfect 6.x Converter Stack Corruption Vulnerability - CVE-2009-0088
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 or view, change, or delete data; or create new accounts with full user rights.
What causes the vulnerability?
This vulnerability requires that a user open a specially crafted WordPerfect 6.x document with Microsoft Office Word 2000.
What are the Microsoft Office WordPerfect 6.x Converter and the Microsoft Office Converter Pack?
The Microsoft Office WordPerfect 6.x Converter helps users convert documents from Corel WordPerfect 6.x file formats to MicrosoftOffice Word file formats. The WordPerfect 6.x Converter is included in all versions of Office and is also available separately in the Microsoft Office Converter Pack.
The Microsoft Office Converter Pack combines file converters and filters that were not included in earlier versions of Office. These converters and filters allow Office to use additional document formats that were not natively supported. The Microsoft Office Converter Pack is available as a Web download.
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?
In an e-mail attack scenario, an attacker could exploit the vulnerability by sending a specially crafted WordPerfect 6.x file to the user and by convincing the user to open the file.
In a Web-based attack scenario, an attacker would have to host a Web site that contains a WordPerfect 6.x document 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 that takes them to the attacker's web site.
What systems are primarily at risk from the vulnerability?
All systems where WordPad is used to open up Word documents from untrusted sources, such as workstations or terminal servers, are primarily at risk of 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…
What does the update do?
The update removes the vulnerability by modifying the way that Word validates the length of a string when parsing a WordPerfect document.
When this security bulletin was issued, had this vulnerability been publicly disclosed?
No, 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
WordPad Word 97 Text Converter Stack Overflow Vulnerability - CVE-2009-0235
A remote code execution vulnerability exists in WordPad as a result of memory corruption when a user opens a specially crafted Word file.
To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2009-0235.
Mitigating Factors for WordPad Word 97 Text Converter Stack Overflow Vulnerability - CVE-2009-0235
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. After they click the link, they would be prompted to perform several actions. An attack could only occur after they performed these actions.
•
The vulnerability could not be exploited automatically through e-mail. For an attack to be successful a user must open an attachment that is sent in an e-mail message.
•
An attacker who successfully exploited this vulnerability could gain the same privileges as the user. Users whose accounts are configured to have fewer privileges on the system could be less impacted than users who operate with administrative privileges.
•
A website attempting to exploit the vulnerability would cause a dialog box to appear. The user would be prompted to decide if they wanted to open the file or not, unless the user had previously unchecked the option "Always ask before opening this type of file."
Top of sectionTop of section
Workarounds for WordPad Word 97 Text Converter Stack Overflow Vulnerability - CVE-2009-0235
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 or save Microsoft Office, RTF or Write 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. This includes all files that have .wri, .rtf, and .doc file extensions as well files with other extensions. Be aware that WordPad could also be used to open specially crafted documents regardless of the file name extension.
•
Disable the Word 6 converter by restricting access to mswrd8.wpc
An administrator can apply an access control list to the affected converter to ensure it is no longer loaded by WordPad. This effectively prevents exploitation of the issue.
In order to apply the access list, run the following commands from the command prompt. Note that some of these may result in an error message, this is expected.
echo y| cacls "%ProgramFiles%\Common Files\Microsoft Shared\TextConv\mswrd832.cnv" /E /P everyone:N
echo y| cacls "%ProgramFiles(x86)%\Common Files\Microsoft Shared\TextConv\mswrd832.cnv" /E /P everyone:N
echo y| cacls "%ProgramFiles%\Windows NT\Accessories\mswrd8.wpc" /E /P everyone:N
echo y| cacls "%ProgramFiles%\Windows NT\Accessories\mswrd864.wpc" /E /P everyone:N
echo y| cacls "%ProgramFiles(x86)%\Windows NT\Accessories\mswrd8.wpc" /E /P everyone:N
Impact of workaround. Upon implementing the workaround, the user will no longer be able to convert Word 6 documents to WordPad RTF or Word 2003 documents. Microsoft Office Word will return an error saying, "The file appears to be corrupted."
How to undo the workaround.
echo y| cacls "%ProgramFiles%\Common Files\Microsoft Shared\TextConv\mswrd832.cnv" /E /R everyone
echo y| cacls "%ProgramFiles(x86)%\Common Files\Microsoft Shared\TextConv\mswrd832.cnv" /E /R everyone
echo y| cacls "%ProgramFiles%\Windows NT\Accessories\mswrd8.wpc" /E /R everyone
echo y| cacls "%ProgramFiles%\Windows NT\Accessories\mswrd864.wpc" /E /R everyone
echo y| cacls "%ProgramFiles(x86)%\Windows NT\Accessories\mswrd8.wpc" /E /R everyone
Top of sectionTop of section
FAQ for WordPad Word 97 Text Converter Stack Overflow Vulnerability - CVE-2009-0235
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 or view, change, or delete data; or create new accounts with full user rights.
What causes the vulnerability?
This vulnerability requires that a user open a specially crafted Word 97 document with an affected version of WordPad.
What are WordPad Text Converters?
WordPad is a default component of Microsoft Windows operating systems. Text converters in WordPad allow users who do not have Microsoft Office Word installed to open documents in Microsoft Windows Write (.wri) and Microsoft Office Word 6.0, Microsoft Office Word 97, Microsoft Office Word 2000, and Microsoft Office Word 2002 (.doc) file formats. These text converters also allow users to save documents in the Word 6.0 file format.
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?
In an e-mail attack scenario, an attacker could exploit the vulnerability by sending a specially crafted Word 97 file to the user and by convincing the user to open the file.
In a Web-based attack scenario, an attacker would have to host a Web site that contains a Word 97 document 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. 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.
What systems are primarily at risk from the vulnerability?
All systems where WordPad is used to open Word documents from untrusted sources, such as workstations or 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.
What does the update do?
This update removes the vulnerability by changing the way that the WordPad Text Converters handle opening specially crafted Word 97 files.
When this security bulletin was issued, had this vulnerability been publicly disclosed?
No, 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.
Other Information
Acknowledgments
Microsoft thanks the following for working with us to help protect customers:
•
Sean Larsson and Jun Mao of VeriSign iDefense Labs for reporting the WordPad Word 97 Text Converter Stack Overflow Vulnerability - CVE-2009-0235 (CVE-2009-0235)
•
A researcher with Fortinet’s FortiGuard Global Security Research Team for reporting the WordPad and Office Text Converter Memory Corruption Vulnerability (CVE-2009-0087)
•
A researcher with VeriSign iDefense Labs for reporting the Word 2000 WordPerfect 6.x Converter Stack Corruption Vulnerability (CVE-2009-0088)
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.
Top of sectionTop of section
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
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 (April 14, 2009): Bulletin published.
Related
