Security Bulletin

Microsoft Security Bulletin MS05-055 - Critical

Vulnerability in Windows Kernel Could Allow Elevation of Privilege (908523)

Published: December 13, 2005

Version: 1.0

Summary

Who should read this document: Customers who use Microsoft Windows

Impact of Vulnerability: Elevation of Privilege

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:

• Microsoft Windows 2000 Service Pack 4 - Download the update

Non-Affected Software:

• Microsoft Windows XP Service Pack 1 and Microsoft Windows XP Service Pack 2
• Microsoft Windows XP Professional x64 Edition
• Microsoft Windows Server 2003 and Microsoft Windows Server 2003 Service Pack 1
• Microsoft Windows Server 2003 for Itanium-based Systems and Microsoft Windows Server 2003 with SP1 for Itanium-based Systems
• Microsoft Windows Server 2003 x64 Edition
• Microsoft Windows 98, Microsoft Windows 98 Second Edition (SE), and Microsoft Windows Millennium Edition (ME)

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.

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 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.

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

Severity Ratings and Vulnerability Identifiers:

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.

Frequently asked questions (FAQ) related to this security update

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’m 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 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 additional support for Windows NT 4.0 SP6a and Windows 2000 Service Pack 3 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.

Can I use the Microsoft Baseline Security Analyzer (MBSA) 1.2.1 to determine whether this update is required?
Yes. MBSA 1.2.1 will determine whether this update is required. For more information about MBSA, visit the MBSA Web site.

Can I use the Microsoft Baseline Security Analyzer (MBSA) 2.0 to determine whether this update is required?
Yes. MBSA 2.0 will determine whether this update is required. MBSA 2.0 can detect security updates for products that Microsoft Update supports. For more information about MBSA, visit the MBSA Web site.

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

Yes. SMS can help detect and deploy this security update. For information about SMS, visit the SMS Web site. The Security Update Inventory Tool can be used by SMS for detecting security updates that are offered by Windows Update, that are supported by Software Update Services, and other security updates that are supported by MBSA 1.2.1. For more information about the Security Update Inventory Tool, see 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 2003 Inventory Tool for Microsoft Updates can be used by SMS for detecting 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, see the following Microsoft Web site.

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

Vulnerability Details

Windows Kernel Vulnerability - CAN-2005-2827:

A privilege elevation vulnerability exists in the way that asynchronous procedure calls are processed within the kernel. This vulnerability could allow a logged on user to take complete control of the system.

Mitigating Factors for Windows Kernel Vulnerability - CAN-2005-2827:

• An attacker must have valid logon credentials and be able to log on locally to exploit this vulnerability. The vulnerability could not be exploited remotely or by anonymous users.

Workarounds for Windows Kernel Vulnerability - CAN-2005-2827:

We have not identified any workarounds for this vulnerability.

FAQ for Windows Kernel Vulnerability - CAN-2005-2827:

What is the scope of the vulnerability?

This is a privilege elevation vulnerability. 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. To attempt to exploit the vulnerability, an attacker must be able to log on locally to the system and run a program.

What causes the vulnerability?
The method used to process items in the asynchronous procedure call (APC) queue list.

What is an asynchronous procedure call (APC)?
An asynchronous procedure call (APC) is a function that executes asynchronously in the context of a particular thread. For more information, please visit the following Microsoft web site.

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?
To try to exploit the vulnerability, an attacker must be able to log on locally to a system and run a program.

To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially-crafted application that could exploit the vulnerability and gain complete control over the affected system.

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 do not have sufficient administrative permissions are given the ability to log on to servers and to run programs. However, best practices strongly discourage allowing this.

Could the vulnerability be exploited over the Internet?
No. An attacker must be able to log on to the specific system that is targeted for attack. An attacker cannot load and run a program remotely by using this vulnerability.

What does the update do?
The update addresses the vulnerability by modifying the way that Asynchronous Procedure Calls (APC) queues are processed.

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.

Security Update Information

Affected Software:

For information about the specific security update for your affected software, click the appropriate link:

Windows 2000 (all versions)

Prerequisites
For Windows 2000, this security update requires Service Pack 4 (SP4). For Small Business Server 2000, this security update requires Small Business Server 2000 Service Pack 1a (SP1a) or Small Business Server 2000 running with Windows 2000 Server Service Pack 4 (SP4).

The software that is listed 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.

For more information about how to obtain the latest service pack, see Microsoft Knowledge Base Article 260910.

Inclusion in Future Service Packs:
The update for this issue may be included in a future Update Rollup.

Installation Information

This security update supports the following setup switches.

Note You can combine these switches into one command. For backward compatibility, the security update also supports the setup switches that the earlier version of the Setup program uses. For more information about the supported installation switches, see Microsoft Knowledge Base Article 262841. For more information about the Update.exe installer, visit the Microsoft TechNet Web site. For more information about the terminology that appears in this bulletin, such as hotfix, see Microsoft Knowledge Base Article 824684.

Deployment Information

To install the security update without any user intervention, use the following command at a command prompt for Windows 2000 Service Pack 4:

Windows2000-kb908523-x86-enu /quiet

Note Use of the /quiet switch will suppress all messages. This includes suppressing failure messages. Administrators should use one of the supported methods to verify the installation was successful when they use the /quiet switch. Administrators should also review the KB908523.log file for any failure messages when they use this switch.

To install the security update without forcing the system to restart, use the following command at a command prompt for Windows 2000 Service Pack 4:

Windows2000-kb908523-x86-enu /norestart

For more information about how to deploy this security update with Software Update Services, visit the Software Update Services Web site. For more information about how to deploy this security update using Windows Server Update Services, visit the Windows Server Update Services Web site. This security update will also be available through the Microsoft Update Web site.

Restart Requirement

You must restart your system after you apply this security update. For more information about the reasons why you may be prompted to restart your computer, see Microsoft Knowledge Base Article 887012.

Removal Information

To remove this security update, use the Add or Remove Programs tool in Control Panel.

System administrators can also use the Spuninst.exe utility to remove this security update. The Spuninst.exe utility is located in the %Windir%\$NTUninstallKB908523$\Spuninst folder.

File Information

The English version of this security update has the file attributes that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.

Windows 2000 Service Pack 4 and Small Business Server 2000:

Verifying that the Update Has Been Applied

• Microsoft Baseline Security Analyzer
  To verify that a security update has been applied to an affected system, you can use the Microsoft Baseline Security Analyzer (MBSA) tool. MBSA allows administrators to scan local and remote systems for missing security updates and for common security misconfigurations. For more information about MBSA, visit the Microsoft Baseline Security Analyzer Web site.

• File Version Verification
  Note Because there are several versions of Microsoft Windows, the following steps may be different on your computer. If they are, see your product documentation to complete these steps.

  1. Click Start, and then click Search.
  2. In the Search Results pane, click All files and folders under Search Companion.
  3. In the All or part of the file name box, type a file name from the appropriate file information table, and then click Search.
  4. In the list of files, right-click a file name from the appropriate file information table, and then click Properties. Note Depending on the version of the operating system or programs installed, some of the files that are listed in the file information table may not be installed.
  5. On the Version tab, determine the version of the file that is installed on your computer by comparing it to the version that is documented in the appropriate file information table. Note Attributes other than the file version may change during installation. Comparing other file attributes to the information in the file information table is not a supported method of verifying that the update has been applied. Also, in certain cases, files may be renamed during installation. If the file or version information is not present, use one of the other available methods to verify update installation.

• Registry Key Verification
  You may also be able to verify the files that this security update has installed by reviewing the following registry key:

  HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows 2000\SP5\KB908523\Filelist

  Note This registry key may not contain a complete list of installed files. Also, this registry key may not be created correctly when an administrator or an OEM integrates or slipstreams the 908523 security update into the Windows installation source files.

Other Information

Acknowledgments

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

• eEye Digital Security for reporting the Windows Kernel Vulnerability - (CAN-2005-2827).

Obtaining Other Security Updates:

Updates for other security issues are available at the following locations:

• Security updates are available in the Microsoft Download Center. You can find them most easily by doing a keyword search for "security_patch."
• Updates for consumer platforms are available at the Microsoft Update Web site.

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.

Security Resources:

• The Microsoft TechNet Security Web site provides additional information about security in Microsoft products.
• Microsoft Software Update Services
• Microsoft Windows Server Update Services
• Microsoft Baseline Security Analyzer (MBSA)
• Windows Update
• Microsoft Update
• Windows Update Catalog: For more information about the Windows Update Catalog, see Microsoft Knowledge Base Article 323166.
• Office Update

Software Update Services:

By using Microsoft Software Update Services (SUS), administrators can quickly and reliably deploy the latest critical updates and security updates to Windows 2000 and Windows Server 2003-based servers, and to desktop systems that are running Windows 2000 Professional or Windows XP Professional.

For more information about how to deploy security updates by using Software Update Services, visit the Software Update Services Web site.

Windows Server Update Services:

By using Windows Server Update Services (WSUS), administrators can quickly and reliably deploy the latest critical updates and security updates for Windows 2000 operating systems and later, Office XP and later, Exchange Server 2003, and SQL Server 2000 onto Windows 2000 and later operating systems.

For more information about how to deploy security updates using Windows Server Update Services, visit the Windows Server Update Services Web site.

Systems Management Server:

Microsoft Systems Management Server (SMS) delivers a highly-configurable enterprise solution for managing updates. By using SMS, administrators can identify Windows-based systems that require security updates and can perform controlled deployment of these updates throughout the enterprise with minimal disruption to end users. For more information about how administrators can use SMS 2003 to deploy security updates, visit the SMS 2003 Security Patch Management Web site. SMS 2.0 users can also use Software Updates Service Feature Pack to help deploy security updates. For information about SMS, visit the SMS Web site.

Note SMS uses the Microsoft Baseline Security Analyzer, the Microsoft Office Detection Tool, and the Enterprise Update Scanning Tool to provide broad support for security bulletin update detection and deployment. Some software updates may not be detected by these tools. Administrators can use the inventory capabilities of the SMS in these cases to target updates to specific systems. For more information about this procedure, visit the following Web site. Some security updates require administrative rights following a restart of the system. Administrators can use the Elevated Rights Deployment Tool (available in the SMS 2003 Administration Feature Pack and in the SMS 2.0 Administration Feature Pack) to install these updates.

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 (December 13, 2005): Bulletin published.

Built at 2014-04-18T13:49:36Z-07:00