SecurityvulnsSECURITYVULNS:DOC:20032Microsoft Security Bulletin MS08-036 – Important Vulnerabilities in Pragmatic General Multicast (PGM) Could Allow Denial of Service (950762)
Microsoft Security Bulletin MS08-036 – Important
Vulnerabilities in Pragmatic General Multicast (PGM) Could Allow Denial of Service (950762)
Published: June 10, 2008
Version: 1.0
General Information
Executive Summary
This security update resolves two privately reported vulnerabilities in the Pragmatic General Multicast (PGM) protocol that could allow a denial of service if malformed PGM packets are received by an affected system. An attacker who successfully exploited this vulnerability could cause a user’s system to become non-responsive and to require a restart to restore functionality. Note that the denial of service vulnerability would not allow an attacker to execute code or to elevate their user rights, but it could cause the affected system to stop accepting requests.
This security update is rated Important for all supported editions of Windows XP and Windows Server 2003 and rated Moderate for all supported editions of Windows Vista and Windows Server 2008. For more information, see the subsection, Affected and Non-Affected Software, in this section.
The security update addresses these vulnerabilities by modifying the way PGM parses malformed packets. For more information about the vulnerability, see the Frequently Asked Questions (FAQ) subsection for the specific vulnerability entry under the next section, Vulnerability Information.
Recommendation. Microsoft recommends that customers apply the update at the earliest opportunity.
Known Issues. None
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Affected and Non-Affected Software
The following software have been tested to determine which versions or editions are affected. Other versions or editions are either past their support life cycle or are not affected. To determine the support life cycle for your software version or edition, visit Microsoft Support Lifecycle.
Affected Software
Operating System Maximum Security Impact Aggregate Severity Rating Bulletins Replaced by this Update
Windows XP Service Pack 2
Denial of Service
Important
MS06-052
Windows XP Service Pack 3
Denial of Service
Important
None
Windows XP Professional x64 Edition and Windows XP Professional x64 Edition Service Pack 2
Denial of Service
Important
None
Windows Server 2003 Service Pack 1 and Windows Server 2003 Service Pack 2
Denial of Service
Important
None
Windows Server 2003 x64 Edition and Windows Server 2003 x64 Edition Service Pack 2
Denial of Service
Important
None
Windows Server 2003 with SP1 for Itanium-based Systems and Windows Server 2003 with SP2 for Itanium-based Systems
Denial of Service
Important
None
Windows Vista and Windows Vista Service Pack 1
Denial of Service
Moderate
None
Windows Vista x64 Edition and Windows Vista x64 Edition Service Pack 1
Denial of Service
Moderate
None
Windows Server 2008 for 32-bit Systems*
Denial of Service
Moderate
None
Windows Server 2008 for x64-based Systems*
Denial of Service
Moderate
None
Windows Server 2008 for Itanium-based Systems
Denial of Service
Moderate
None
*Supported editions of Windows Server 2008 are not affected if installed using the Server Core installation option. For more information on this installation option, see Server Core. Note that the Server Core installation option does not apply to certain editions of Windows Server 2008; see Compare Server Core Installation Options.
Non-Affected Software
Operating System
Windows 2000 Service Pack 4
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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 950762.
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.
I am using an older release of the software discussed in this security bulletin. What should I do?
The affected software listed in this bulletin have been tested to determine which releases are affected. Other releases are past their support life cycle. To determine the support life cycle for your software release, visit Microsoft Support Lifecycle.
It should be a priority for customers who have older releases of the software to migrate to supported releases to prevent potential exposure to vulnerabilities. For more information about the Windows Product Lifecycle, visit Microsoft Support Lifecycle. For more information about the extended security update support period for these software versions or editions, visit Microsoft Product Support Services.
Customers who require custom support for older releases must contact their Microsoft account team representative, their Technical Account Manager, or the appropriate Microsoft partner representative for custom support options. Customers without an Alliance, Premier, or Authorized Contract can contact their local Microsoft sales office. For contact information, visit Microsoft Worldwide Information, select the country, and then click Go to see a list of telephone numbers. When you call, ask to speak with the local Premier Support sales manager. For more information, see the Windows Operating System Product Support Lifecycle FAQ.
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Vulnerability Information
Severity Ratings and Vulnerability Identifiers
Vulnerability Severity Rating and Maximum Security Impact by Affected Software
Affected Software PGM Invalid Length Vulnerability - CVE-2008-1440 PGM Malformed Fragment Vulnerability - CVE-2008-1441 Aggregate Severity Rating
Windows XP Service Pack 2
Important
Denial of Service
Moderate
Denial of Service
Important
Windows XP Service Pack 3
Important
Denial of Service
Moderate
Denial of Service
Important
Windows XP Professional x64 Edition and Windows XP Professional x64 Edition Service Pack 2
Important
Denial of Service
Moderate
Denial of Service
Important
Windows Server 2003 Service Pack 1 and Windows Server 2003 Service Pack 2
Important
Denial of Service
Moderate
Denial of Service
Important
Windows Server 2003 x64 Edition and Windows Server 2003 x64 Edition Service Pack 2
Important
Denial of Service
Moderate
Denial of Service
Important
Windows Server 2003 with SP1 for Itanium-based Systems and Windows Server 2003 with SP2 for Itanium-based Systems
Important
Denial of Service
Moderate
Denial of Service
Important
Windows Vista and Windows Vista Service Pack 1
Not affected
Moderate
Denial of Service
Moderate
Windows Vista x64 Edition and Windows Vista x64 Edition Service Pack 1
Not affected
Moderate
Denial of Service
Moderate
Windows Server 2008 for 32-bit Systems*
Not affected
Moderate
Denial of Service
Moderate
Windows Server 2008 for x64-based Systems*
Not affected
Moderate
Denial of Service
Moderate
Windows Server 2008 for Itanium-based Systems
Not affected
Moderate
Denial of Service
Moderate
*Supported editions of Windows Server 2008 are not affected if installed using the Server Core installation option. For more information on this installation option, see Server Core. Note that the Server Core installation option does not apply to certain editions of Windows Server 2008; see Compare Server Core Installation Options.
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PGM Invalid Length Vulnerability - CVE-2008-1440
A denial of service vulnerability exists in implementations of the Pragmatic General Multicast (PGM) protocol on Microsoft Windows XP and Windows Server 2003. The vulnerability is due to improper validation of specially crafted PGM packets. An attacker who successfully exploited this vulnerability could cause the computer to become non-responsive and require a restart to restore functionality.
To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2008-1440.
Mitigating Factors for PGM Invalid Length Vulnerability - CVE-2008-1440
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:
•
On systems running Windows XP and Windows Server 2003, Pragmatic General Multicast (PGM) is only enabled when Microsoft Message Queuing (MSMQ) 3.0 is installed. The MSMQ service is not installed by default.
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Workarounds for PGM Invalid Length Vulnerability - CVE-2008-1440
Microsoft has not identified any workarounds for this vulnerability.
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FAQ for PGM Invalid Length Vulnerability - CVE-2008-1440
What is the scope of the vulnerability?
This is a denial of service vulnerability. A remote, anonymous attacker who exploited this vulnerability could cause the affected system to become non-responsive until the system is restarted. Note that the denial of service vulnerability would not allow an attacker to execute code or to elevate their user rights, but it could cause the affected system to stop accepting requests.
What causes the vulnerability?
The protocol’s parsing code does not properly validate the option length field of a PGM packet. If an affected system receives a specially crafted PGM packet with an invalid option length field, the parser enters an infinite loop and eventually causes the system to become non-responsive.
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 responsibility for the reliability of communications. 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, see the following MSDN Article.
What is Microsoft Message Queuing?
Microsoft Message Queuing (MSMQ) is a component of the Windows operating system that allows cooperating applications to send and receive messages to each other, even if the intended recipient application is not running or the computer on which the sender or recipient application is running is disconnected from the network. Messages are stored and forwarded by MSMQ until they reach the destination queue. Later, when a recipient application runs, it can retrieve the messages from the queue. MSMQ decouples sender and recipient applications so they do not need to run at the same time. Message Queuing provides built-in enhanced security, transaction support, and other features. For more information on MSMQ, see MSMQ: Frequently Asked Questions.
What might an attacker use the vulnerability to do?
An attacker who successfully exploited this vulnerability could cause a user’s system to become non-responsive and require a restart to restore functionality.
How could an attacker exploit the vulnerability?
An attacker could try to exploit the vulnerability by sending a specially crafted PGM packet to an affected system. The packet could then cause the affected system to become non-responsive until restarted.
What systems are primarily at risk from the vulnerability?
Workstations and servers that have installed MSMQ or are running a PGM-supported application (that listens for PGM packets) are primarily at risk.
What does the update do?
The update removes the vulnerability by correctly validating the option length field of PGM packets.
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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PGM Malformed Fragment Vulnerability - CVE-2008-1441
A denial of service vulnerability exists in implementations of the Pragmatic General Multicast (PGM) protocol on Microsoft Windows XP, Windows Server 2003, Windows Vista, and Windows Server 2008. The protocol’s parsing code does not properly validate specially crafted PGM fragments and will cause the affected system to become non-responsive until the attack has ceased.
To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2008-1441.
Mitigating Factors for PGM Malformed Fragment Vulnerability - CVE-2008-1441
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:
•
On systems running Windows XP or Windows Server 2003, Pragmatic General Multicast (PGM) is only enabled when Microsoft Message Queuing (MSMQ) 3.0 is installed. The MSMQ service is not installed by default.
•
On systems running Windows Vista or Windows Server 2008, Pragmatic General Multicast (PGM) is only enabled when Microsoft Message Queuing (MSMQ) 4.0 is installed and PGM is specifically enabled. The MSMQ service is not installed by default. When the MSMQ service is installed, the PGM protocol is available but not enabled by default.
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Workarounds for PGM Malformed Fragment Vulnerability - CVE-2008-1441
Microsoft has not identified any workarounds for this vulnerability.
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FAQ for PGM Malformed Fragment Vulnerability - CVE-2008-1441
What is the scope of the vulnerability?
This is a denial of service vulnerability. A remote, anonymous attacker who exploited this vulnerability could cause the affected system to become non-responsive. Note that the denial of service vulnerability would not allow an attacker to execute code or to elevate their user rights, but it could cause the affected system to stop accepting requests.
What causes the vulnerability?
The protocol’s parsing code does not properly handle malformed PGM packets that contain an invalid fragment option.
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 responsibility for the reliability of communications. 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, see the following MSDN Article.
What is Microsoft Message Queuing?
Microsoft Message Queuing (MSMQ) is a component of the Windows operating system that allows cooperating applications to send and receive messages to each other, even if the intended recipient application is not running or the computer on which the sender or recipient application is running is disconnected from the network. Messages are stored and forwarded by MSMQ until they reach the destination queue. Later, when a recipient application runs, it can retrieve the messages from the queue. MSMQ decouples sender and recipient applications so they do not need to run at the same time. Message Queuing provides built-in enhanced security, transaction support, and other features. For more information on MSMQ, see MSMQ: Frequently Asked Questions.
What might an attacker use the vulnerability to do?
An attacker who successfully exploited this vulnerability could cause a user’s system to become non-responsive.
How could an attacker exploit the vulnerability?
An attacker could try to exploit the vulnerability by sending specially crafted PGM packets to an affected system. The packets could then cause the affected system to become non-responsive. The system will return to normal functionality when all specially crafted packets have been processed or the system is restarted. Once restarted, the system will again become nonresponsive if the attacker continues to send the specially crafted PGM packets.
What systems are primarily at risk from the vulnerability?
Workstations and servers that have installed MSMQ or are running a PGM-supported application (that listens for PGM packets) are primarily at risk.
What does the update do?
The update removes the vulnerability by correctly validating the fragment options of PGM packets.
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.
Other Information
Support
•
Customers in the U.S. and Canada can receive technical support from Microsoft Product Support Services at 1-866-PCSAFETY. There is no charge for support calls that are associated with security updates.
•
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 (June 10, 2008): Bulletin published.
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