Microsoft Security Bulletin MS06-054 Vulnerability in Microsoft Publisher Could Allow Remote Code Execution (910729)

Microsoft Security Bulletin MS06-054
Vulnerability in Microsoft Publisher Could Allow Remote Code Execution (910729)
Published: September 12, 2006

Version: 1.0
Summary

Who Should Read this Document: Customers who use Microsoft Publisher

Impact of Vulnerability: Remote Code Execution

Maximum Severity Rating: Critical

Recommendation: Customers should apply the update immediately

Security Update Replacement: None

Caveats: Microsoft Knowledge Base Article 910729 documents the currently known issues that customers may experience when they install this security update. The article also documents recommended solutions for these issues. For more information, see Microsoft Knowledge Base Article 910729.

Tested Software and Security Update Download Locations:

Affected Software:
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Microsoft Office 2000 Service Pack 3 — Download the update (KB894540)
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Office Publisher 2000
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Microsoft Office XP Service Pack 3 — Download the update (KB894541)
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Office Publisher 2002
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Microsoft Office 2003 Service Pack 1 and Service Pack 2 — Download the update (KB894542)
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Office Publisher 2003

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 a newly discovered, privately reported vulnerability. The vulnerability is documented in the "Vulnerability Details" section of this bulletin.

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.

We recommend that customers apply the update immediately.

Severity Ratings and Vulnerability Identifiers:
Vulnerability Identifiers Impact of Vulnerability Publisher 2000 Publisher 2002 Publisher 2003

Microsoft Publisher Vulnerability - CVE-2006-0001

Remote Code Execution

Critical

Important

Important

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

I do not have Microsoft Publisher installed, but I do have other Microsoft Office applications installed. Why am I being offered the security update?
This vulnerability only affects Microsoft Publisher. However, other Microsoft Office applications use some of the same files as Publisher that the security update affects. We recommend installing the update to prevent the security update from being offered again.

I have some Microsoft Office applications installed but I do not have Microsoft Publisher installed and I install this update. Will the update continue to be reoffered?
No, you will not be reoffered this update unless you install Publisher.

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.
Software MBSA 1.2.1 MBSA 2.0

Microsoft Publisher 2000

Yes

No

Microsoft Publisher 2002

Yes

Yes

Microsoft Publisher 2003

Yes

Yes

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 Publisher 2000

Yes

Yes

Microsoft Publisher 2002

Yes

Yes

Microsoft Publisher 2003

Yes

Yes

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.

For more detailed information, see Microsoft Knowledge Base Article 910723.
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Vulnerability Details

Microsoft Publisher Vulnerability - CVE-2006-0001

A remote code execution vulnerability exists in Publisher. An attacker could exploit this vulnerability when Publisher parses a file with a malformed string.

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 Publisher Vulnerability - CVE-2006-0001:
•

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.
•

In a Web-based attack scenario, an attacker would have to host a Web site that contains a Word file 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 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 vulnerability cannot 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.
•

Users who have installed and are using the Office Document Open Confirmation Tool for Office 2000 will be prompted with Open, Save, or Cancel before opening a document.
•

By default, Publisher is only installed on the Professional Suites of Office.
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Workarounds for Microsoft Publisher Vulnerability - CVE-2006-0001:

Microsoft has tested the following workarounds. Although 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 Publisher files that you receive from un-trusted sources or that you receive unexpectedly from trusted sources.

This vulnerability could be exploited when Publisher opens a file.
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FAQ for Microsoft Publisher Vulnerability - CVE-2006-0001:

What is the scope of the vulnerability?
A remote code execution vulnerability exists in Publisher. An attacker could exploit this vulnerability when Publisher parses a file with a malformed string.

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?
Publisher does not perform sufficient data validation when processing the contents of a .pub file. When Publisher opens a specially crafted Publisher file and parses a malformed string, 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 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.

In a Web-based attack scenario, an attacker would have to host a Web site that contains a Word file 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 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.

What systems are primarily at risk from the vulnerability?
Workstations and terminal servers are primarily at risk. Servers could be at more risk if administrators allow users to log on to servers and to run programs. However, best practices strongly discourage allowing this.

What does the update do?
The update removes the vulnerability by modifying the way that Publisher parses the file and validates the length of a string before passing it to the allocated buffer.

Does this update contain any changes to functionality?
Yes. After the update for Publisher 2000 or Publisher 2002 is installed, users will not be able to open Publisher 2.0 files anymore. For more information, see Microsoft Knowledge Base Article 924685. In addition, if a user opens a malformed Publisher file, Publisher may potentially crash but will not be exploitable.

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.

Acknowledgments

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

Stuart Pearson of Computer Terrorism for reporting the Microsoft Publisher Vulnerability - CVE-2006-0001

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:
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V1.0 (September 12, 2006): Bulletin published.