Microsoft Security Bulletin MS06-039 Vulnerabilities in Microsoft Office Filters Could Allow Remote Code Execution (915384)

Microsoft Security Bulletin MS06-039
Vulnerabilities in Microsoft Office Filters Could Allow Remote Code Execution (915384)
Published: July 11, 2006

Version: 1.0
Summary

Who Should Read this Document: Customers who use Microsoft Office

Impact of Vulnerability: Remote Code Execution

Maximum Severity Rating: Critical

Recommendation: Customers should apply the update immediately

Security Update Replacement: None

Caveats: None

Tested Software and Security Update Download Locations:

Affected Software:
•

Microsoft Office 2003 Service Pack 1 or Service Pack 2 - Download the update (KB914455)
•

Microsoft Project 2003
•

OneNote 2003
•

Microsoft Office XP Service Pack 3 - Download the update (KB914796)
•

Microsoft Office 2000 Service Pack 3 - Download the update (KB914797)
•

Microsoft Project 2002 - Download the update (KB920102)
•

Microsoft Project 2000 - Download the update (KB920101)
•

Microsoft Works Suites:
•

Microsoft Works Suite 2004 -Download the update (KB914796) (same as the Microsoft Office XP update)
•

Microsoft Works Suite 2005 -Download the update (KB914796) (same as the Microsoft Office XP update)
•

Microsoft Works Suite 2006 -Download the update (KB914796) (same as the Microsoft Office XP update)

Non- Affected Software:
•

Microsoft Office Viewers
•

Microsoft Office 2004 for Mac
•

Microsoft Office v. X for Mac

The software in this list has been tested to determine whether the versions are affected. Other versions either no longer include security update support or may not be affected. To determine the support life cycle for your product and version, visit the Microsoft Support Lifecycle Web site.
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General Information

Executive Summary

Executive Summary:

This update resolves two newly discovered, privately reported vulnerabilities. Each vulnerability is documented in its own "Vulnerability Details" section in this bulletin.

On vulnerable versions of Office, if a user is logged on with administrative user rights, an attacker who successfully exploited this vulnerability could take complete control of the client workstation. 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.

We recommend that customers apply the update immediately.

Severity Ratings and Vulnerability Identifiers:
Vulnerability Identifiers Impact of Vulnerability Microsoft Office 2003 Microsoft Project 2003 Microsoft OneNote 2003 Microsoft Office XP Microsoft Office 2000 Microsoft Project 2002 Microsoft Project 2000

Microsoft Office Remote Code Execution Using a Malformed PNG Vulnerability - CVE-2006-0033

Remote Code Execution

Important

Important

Important

Important

Critical

Important

Not Applicable

Microsoft Office Remote Code Execution Using a Malformed GIF Vulnerability - CVE-2006-0007

Remote Code Execution

Moderate

Moderate

Moderate

Moderate

Moderate

Moderate

Moderate

Aggregate Severity of All Vulnerabilities

Important

Important

Important

Important

Critical

Important

Moderate

Note The severity ratings for Microsoft Works Suite maps to the Microsoft Word versions as follows:
•

The Microsoft Works Suite 2004, 2005, and 2006 severity rating is the same as the Microsoft Office XP severity rating.

This assessment is based on the types of systems that are affected by the vulnerability, their typical deployment patterns, and the effect that exploiting the vulnerability would have on them.
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Frequently Asked Questions (FAQ) Related to this Security Update

Why does Microsoft Works Suite appear in the Affected Software list?
Microsoft Works Suite appears in the Affected Software list because it includes Microsoft Word. Microsoft Works users should use Office Update to detect and to install the appropriate update.

Can I use the Microsoft Baseline Security Analyzer (MBSA) to determine whether this update is required?

The following table provides the MBSA detection summary for this security update.
Product MBSA 1.2.1 MBSA 2.0

Microsoft Office 2003

Yes

Yes

Microsoft Office XP

Yes

Yes

Microsoft Office 2000

Yes

No

Microsoft Project 2002

Yes

Yes

Microsoft Project 2000

Yes

No

Note MBSA 1.2.1 uses an integrated version of the Office Detection Tool (ODT) which does not support remote scans of this security update. For more information about MBSA, visit the MBSA Web site.

For more information about MBSA, visit the MBSA Web site. For more information about the programs that Microsoft Update and MBSA 2.0 currently do not detect, see Microsoft Knowledge Base Article 895660.

Can I use Systems Management Server (SMS) to determine whether this update is required?

The following table provides the SMS detection summary for this security update.
Software SMS 2.0 SMS 2003

Microsoft Office 2003

Yes

Yes

Microsoft Office XP

Yes

Yes

Microsoft Office 2000

Yes

No

Microsoft Project 2002

Yes

Yes

Microsoft Project 2000

Yes

No

SMS uses MBSA for detection. Therefore, SMS has the same limitation that is listed earlier in this bulletin related to programs that MBSA does not detect.

For SMS 2.0, the SMS SUS Feature Pack, which includes the Security Update Inventory Tool, can be used by SMS to detect security updates. SMS SUIT uses the MBSA 1.2.1 engine for detection. For more information about the Security Update Inventory Tool, visit the following Microsoft Web site. For more information about the limitations of the Security Update Inventory Tool, see Microsoft Knowledge Base Article 306460. The SMS SUS Feature Pack also includes the Microsoft Office Inventory Tool to detect required updates for Microsoft Office applications.

For SMS 2003, the SMS 2003 Inventory Tool for Microsoft Updates can be used by SMS to detect security updates that are offered by Microsoft Update and that are supported by Windows Server Update Services. For more information about the SMS 2003 Inventory Tool for Microsoft Updates, visit the following Microsoft Web site. SMS 2003 can also use the Microsoft Office Inventory Tool to detect required updates for Microsoft Office applications.

For more information about SMS, visit the SMS Web site.
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Vulnerability Details

Microsoft Office Remote Code Execution Using a Malformed PNG Vulnerability- CVE-2006-0033

A remote code execution vulnerability exists in Office and could be exploited when Office opened a malformed PNG file. An attacker could exploit the vulnerability by constructing a specially crafted PNG file that could allow remote code execution.

If a user were 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 affected than users who operate with administrative user rights.

Mitigating Factors for Microsoft Office Remote Code Execution Using a Malformed PNG Vulnerability - CVE-2006-0033:
•

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.
•

The vulnerability can 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.
•

On Office XP and Office 2003, this vulnerability could not be exploited automatically through a Web-based attack scenario. An attacker would have to host a Web site that contains an Office file that is used to attempt 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 persuade them to visit the Web site, typically by getting them to click a link that takes them to the attacker's site.
•

The default PNG filter provided by the operating system without Office installed is not affected by this vulnerability.

Note Office 2000 does not prompt the user to Open, Save, or Cancel before opening a document.
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Workarounds for Microsoft Office Remote Code Execution Using a Malformed PNG Vulnerability - CVE-2006-0033:

Microsoft has tested the following workarounds. While these workarounds will not correct the underlying vulnerability, they help block known attack vectors. When a workaround reduces functionality, it is identified in the following section.

Do not open or save Microsoft PNG files that you receive from un-trusted sources or that you received unexpectedly from trusted sources.

This vulnerability could be exploited when a user opens a PNG file.
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FAQ for Office Remote Code Execution Using a Malformed PNG Vulnerability - CVE-2006-0033:

What is the scope of the vulnerability?
A remote code execution vulnerability exists in Office and could be exploited when a user opened a malformed PNG file. An attacker could exploit the vulnerability by constructing a specially crafted PNG file that could allow remote code execution.

If a user were 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 affected than users who operate with administrative user rights.

What causes the vulnerability?
When the Office PNG filter file opens a malformed PNG file, it may corrupt system memory in such a way that an attacker could execute arbitrary code.

What might an attacker use the vulnerability to do?
An attacker who successfully exploited this vulnerability could take complete control of the affected system.

How could an attacker exploit the vulnerability?
In a Web-based attack scenario, an attacker could host a Web site that contains a PNG file 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 persuade 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.

In an e-mail attack scenario, an attacker could exploit the vulnerability by sending a specially-crafted file to the user and by persuading the user to open the file.

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 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 removes the vulnerability by modifying the way that Office parses a PNG file before it passes it to the allocated buffer.

When this security bulletin was issued, had this vulnerability been publicly disclosed?
No. Microsoft received information about this vulnerability through responsible disclosure. Microsoft had not received any information to indicate that this vulnerability had been publicly disclosed when this security bulletin was originally issued.

When this security bulletin was issued, had Microsoft received any reports that this vulnerability was being exploited?
No. Microsoft had not received any information to indicate that this vulnerability had been publicly used to attack customers and had not seen any examples of proof of concept code published when this security bulletin was originally issued.
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Microsoft Office Remote Code Execution Using a Malformed GIF Vulnerability- CVE-2006-0007

A remote code execution vulnerability exists in Office and could be exploited when a user opened a malformed GIF file. An attacker could exploit the vulnerability by constructing a specially crafted GIF file that could allow remote code execution.

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 affected than users who operate with administrative user rights.

Mitigating Factors for Microsoft Office Remote Code Execution Using a Malformed GIF Vulnerability - CVE-2006-0007:
•

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.
•

The vulnerability can 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.
•

On Office XP and Office 2003, this vulnerability could not be exploited automatically through a Web-based attack scenario. An attacker would have to host a Web site that contains an Office file that is used to attempt 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 persuade them to visit the Web site, typically by getting them to click a link that takes them to the attacker's site.
•

The default GIF filter provided by the operating system without Office installed is not affected by this vulnerability.

Note Office 2000 does not prompt the user to Open, Save, or Cancel before opening a document.
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Workarounds for Microsoft Office Remote Code Execution Using a Malformed GIF Vulnerability - CVE-2006-0007:

Microsoft has tested the following workarounds. While these workarounds will not correct the underlying vulnerability, they help block known attack vectors. When a workaround reduces functionality, it is identified in the following section.

Do not open or save Microsoft GIF files that you receive from un-trusted sources or that you received unexpectedly from trusted sources.

This vulnerability could be exploited when a user opens a GIF file.
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FAQ for Office Remote Code Execution Using a Malformed GIF Vulnerability - CVE-2006-0007:

What is the scope of the vulnerability?
A remote code execution vulnerability exists in Office, and could be exploited when a malformed string included in an Office file was parsed by any of the affected Office applications. Such a string might be included in an email attachment processed by one of the affected applications or hosted on a malicious web site. Viewing or previewing a malformed email message in an affected version of Outlook could not lead to exploitation of this vulnerability. An attacker could exploit the vulnerability by constructing a specially crafted Office file that could allow remote code execution.

If a user were 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 affected than users who operate with administrative user rights.

What causes the vulnerability?
When Office opens a specially crafted GIF file, it may corrupt system memory in such a way that an attacker could execute arbitrary code.

What might an attacker use the vulnerability to do?
An attacker who successfully exploited this vulnerability could take complete control of the affected system.

How could an attacker exploit the vulnerability?
In a Web-based attack scenario, an attacker could host a Web site that contains a GIF file 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 persuade 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.

In an e-mail attack scenario, an attacker could exploit the vulnerability by sending a specially-crafted file to the user and by persuading the user to open the file.

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 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 removes the vulnerability by modifying the way that Office parses a PNG file before it passes it to the allocated buffer.

When this security bulletin was issued, had this vulnerability been publicly disclosed?
No. Microsoft received information about this vulnerability through responsible disclosure. Microsoft had not received any information to indicate that this vulnerability had been publicly disclosed when this security bulletin was originally issued.

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

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 11, 2006): Bulletin published.