Microsoft Security Bulletin MS06-052 Vulnerability in Pragmatic General Multicast (PGM) Could Allow Remote Code Execution (919007)

Microsoft Security Bulletin MS06-052
Vulnerability in Pragmatic General Multicast (PGM) Could Allow Remote Code Execution (919007)
Published: September 12, 2006

Version: 1.0
Summary

Who Should Read this Document: Customers who use Microsoft Windows

Impact of Vulnerability: Remote Code Execution

Maximum Severity Rating: Important

Recommendation: Customers should apply the update at the earliest opportunity

Security Update Replacement: None

Caveats: None

Tested Software and Security Update Download Locations:

Affected Software:
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Microsoft Windows XP Service Pack 1 and Microsoft Windows XP Service Pack 2 — Download the update

Non-Affected Software:
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Microsoft Windows 2000 Service Pack 4
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Microsoft Windows XP Professional x64 Edition
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Microsoft Windows Server 2003 and Microsoft Windows Server 2003 Service Pack 1
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Microsoft Windows Server 2003 for Itanium-based Systems and Microsoft Windows Server 2003 with SP1 for Itanium-based Systems
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Microsoft Windows Server 2003 x64 Edition

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.

Note The security updates for Microsoft Windows Server 2003, Windows Server 2003 Service Pack 1, and Windows Server 2003 x64 Edition also apply to Windows Server 2003 R2.
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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.

An attacker who successfully exploited the vulnerability could take complete control of the affected system. The Windows service needed that would allow PGM communications is not installed by default.

We recommend that customers apply the update at the earliest opportunity.

Severity Ratings and Vulnerability Identifiers:
Vulnerability Identifiers Impact of Vulnerability Windows XP Service Pack 1 Windows XP Service Pack 2

PGM Code Execution Vulnerability - CVE-2006-3442

Remote Code Execution

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

Extended security update support for Microsoft Windows 98, Windows 98 Second Edition, or Windows Millennium Edition ended on July 11, 2006. I am still using one of these operating systems; what should I do?
Windows 98, Windows 98 Second Edition, and Windows Millennium Edition have reached the end of their support life cycles. It should be a priority for customers who have these operating system versions to migrate to supported versions to prevent potential exposure to vulnerabilities. For more information about the Windows Product Lifecycle, visit the following Microsoft Support Lifecycle Web site. For more information about the extended security update support period for these operating system versions, visit the Microsoft Product Support Services Web site.

Extended security update support for Microsoft Windows NT Workstation 4.0 Service Pack 6a and Windows 2000 Service Pack 2 ended on June 30, 2004. Extended security update support for Microsoft Windows NT Server 4.0 Service Pack 6a ended on December 31, 2004. Extended security update support for Microsoft Windows 2000 Service Pack 3 ended on June 30, 2005. I am still using one of these operating systems; what should I do?
Windows NT Workstation 4.0 Service Pack 6a, Windows NT Server 4.0 Service Pack 6a, Windows 2000 Service Pack 2, and Windows 2000 Service Pack 3 have reached the end of their support life cycles. It should be a priority for customers who have these operating system versions to migrate to supported versions to prevent potential exposure to vulnerabilities. For more information about the Windows Product Lifecycle, visit the following Microsoft Support Lifecycle Web site. For more information about the extended security update support period for these operating system versions, visit the Microsoft Product Support Services Web site.

Customers who require custom support for these products must contact their Microsoft account team representative, their Technical Account Manager, or the appropriate Microsoft partner representative for custom support options. Customers without an Alliance, Premier, or Authorized Contract can contact their local Microsoft sales office. For contact information, visit the Microsoft Worldwide Information Web site, select the country, 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.

For more information, visit the Windows Operating System FAQ.

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 Windows XP Service Pack 1 and Microsoft Windows XP Service Pack 2

Yes

Yes

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.

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

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.
Product SMS 2.0 SMS 2003

Microsoft Windows XP Service Pack 1 and Microsoft Windows XP Service Pack 2

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

PGM Code Execution Vulnerability - CVE-2006-3442:

There is a remote code execution vulnerability that could allow an attacker to send a specially crafted multicast message to an affected system and execute code on the affected system. The MSMQ service, which is the Windows service needed to allow PGM communications is not installed by default

Mitigating Factors for PGM Code Execution Vulnerability - CVE-2006-3442:
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For customers who require the affected component, firewall best practices and standard default firewall configurations can help protect networks from attacks that originate outside the enterprise perimeter. Best practices recommend that systems that are connected to the Internet have a minimal number of ports exposed.
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Pragmatic General Multicast (PGM) is only supported when Microsoft Message Queuing (MSMQ) 3.0 is installed. The MSMQ service is not installed by default.
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Workarounds for PGM Code Execution Vulnerability - CVE-2006-3442:

We have not identified any workarounds for this vulnerability.
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FAQ for PGM Code Execution Vulnerability - CVE-2006-3442:

What is the scope of the vulnerability?
This is a remote code execution vulnerability. An attacker who successfully exploited this vulnerability could remotely 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.

What causes the vulnerability?
Invalid memory access in the Pragmatic General Multicast (PGM) multicast protocol implementation in Windows XP.

What is Pragmatic General Multicast (PGM)?
PGM is a reliable and scalable multicast protocol that enables receivers to detect loss, request retransmission of lost data, or notify an application of unrecoverable loss. PGM is a receiver-reliable protocol, which means the receiver is responsible for ensuring all data is received, absolving the sender of reception responsibility. PGM is appropriate for applications that require duplicate-free multicast data delivery from multiple sources to multiple receivers. PGM does not support acknowledged delivery, nor does it guarantee ordering of packets from multiple senders. For more information on PGM please see the following MSDN Article.

What is MSMQ and the MSMQ Service?
Microsoft Message Queuing Services (MSMQ) enables applications running at different times to communicate across heterogeneous networks and systems that may be temporarily offline. For more information on PGM please see the following MSDN Article.

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

Who could exploit the vulnerability?
On Windows XP, any anonymous user who could deliver a specially crafted message to the affected system could try to exploit this vulnerability.

How could an attacker exploit the vulnerability?
An attacker could try to exploit the vulnerability by sending a specially crafted message that could communicate with a vulnerable system through MSMQ.

What systems are primarily at risk from the vulnerability?
Windows XP systems that have installed the MSMQ service are primarily at risk from this vulnerability. The service is not installed by default.

Note Windows XP Professional x64 Edition shares its implementation of MSMQ with Windows Server 2003 x64 Edition and is therefore not affected by this vulnerability.

Could the vulnerability be exploited over the Internet?
Yes. An attacker could try to exploit this vulnerability over the Internet. Firewall best practices and standard default firewall configurations can help protect against attacks that originate from the Internet. Microsoft has provided information about how you can help protect your PC. End users can visit the Protect Your PC Web site. IT professionals can visit the Security Guidance Center Web site.

What does the update do?
The update removes the vulnerability by modifying the way that a PGM message is validated before it passes the message 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.

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:
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David Warden of NuPaper Inc. for reporting the PGM Code Execution Vulnerability (CVE-2006-3442).

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, 2005: Bulletin published.