Security Bulletin

Microsoft Security Bulletin MS08-060 - Critical

Vulnerability in Active Directory Could Allow Remote Code Execution (957280)

Published: October 14, 2008 | Updated: October 15, 2008

Version: 1.1

General Information

Executive Summary

This security update resolves a privately reported vulnerability in implementations of Active Directory on Microsoft Windows 2000 Server. The vulnerability could allow remote code execution if an attacker gains access to an affected network. This vulnerability only affects Microsoft Windows 2000 servers configured to be domain controllers. If a Microsoft Windows 2000 server has not been promoted to a domain controller, it will not be listening to Lightweight Directory Access Protocol (LDAP) or LDAP over SSL (LDAPS) queries, and will not be exposed to this vulnerability.

This security update is rated Critical for implementations of Active Directory on Microsoft Windows 2000 Server. For more information, see the subsection, Affected and Non-Affected Software, in this section.

The security update addresses the vulnerability by correctly allocating memory for client LDAP requests. 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 immediately.

Known Issues. None

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

Non-Affected Software

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 957280.

I am running one of the platforms that are listed in the affected software table. Why am I not being offered the update? 
The update will only be offered to systems on which the affected component is both installed and enabled. Microsoft Windows 2000 Server systems not configured in the role of a domain controller are not affected and will not receive this update.

Does this issue also affect Active Directory Application Mode (ADAM) or Active Directory Lightweight Directory Service (AD LDS)? 
No. This issue only affects Microsoft Windows 2000 servers configured as Active Directory domain controllers. No other platforms or services are affected.

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.

Vulnerability Information

Severity Ratings and Vulnerability Identifiers

Active Directory Overflow Vulnerability - CVE-2008-4023

A remote code execution vulnerability exists in implementations of Active Directory on Microsoft Windows 2000 Server. The vulnerability is due to incorrect memory allocation when receiving specially crafted LDAP or LDAPS requests. An attacker who successfully exploited this vulnerability could take complete control of an affected system.

To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2008-4023.

Mitigating Factors for Active Directory Overflow Vulnerability - CVE-2008-4023

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:

• 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.

• This vulnerability only affects Microsoft Windows 2000 servers configured to be domain controllers. If a Microsoft Windows 2000 server has not been promoted to a domain controller, it will not be listening to LDAP or LDAPS queries, and will not be exposed to this vulnerability.
  To confirm whether a server is listening to LDAP or LDAPS queries, run the following command from an administrator command prompt and look to see if it is listening on the LDAP port (389) or the LDAPS port (636):

  netstat -a

  LDAP is enabled if the results contain the following:

  Proto Local Address Foreign Address StateTCP 0.0.0.0:389 0.0.0.0:0 LISTENINGTCP 0.0.0.0:636 0.0.0.0:0 LISTENING

Workarounds for Active Directory Overflow Vulnerability - CVE-2008-4023

Workaround refers to a setting or configuration change that does not correct the underlying vulnerability but would help block known attack vectors before you apply the update. Microsoft has tested the following workarounds and states in the discussion whether a workaround reduces functionality:

• Block TCP ports 389 and 636 at the perimeter firewall
  These ports are used to initiate a connection with the affected component. Blocking it at the enterprise firewall, both inbound and outbound, will help prevent systems that are behind that firewall from attempts to exploit this vulnerability. We recommend that you block all unsolicited inbound communication from the Internet to help prevent attacks that may use other ports. For more information about ports, see TCP and UDP Port Assignments. For more information about the Windows Firewall, see How to Configure Windows Firewall on a Single Computer.

FAQ for Active Directory Overflow Vulnerability - CVE-2008-4023

What is the scope of the vulnerability? 
This is a remote code execution vulnerability. An attacker who successfully exploited this vulnerability could take complete control of an affected system remotely. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

Note. Attacks attempting to exploit this vulnerability could also result in a denial of service condition. An attacker could also exploit this vulnerability to force the system to restart. However, since remote code execution is possible, the aggregate scope is larger than only a denial of service.

What causes the vulnerability? 
The LDAP service incorrectly allocates memory for specially crafted LDAP requests.

What is Active Directory? 
The main purpose of Active Directory is to provide central authentication and authorization services for Windows-based computers.

What is LDAP? 
Lightweight Directory Access Protocol (LDAP) is an open network protocol standard designed to provide access to distributed directories.

What is LDAP over SSL? 
By default, LDAP traffic is transmitted unsecured. However, it is possible to make LDAP traffic confidential and secure by using Secure Sockets Layer (SSL) / Transport Layer Security (TLS) technology. Administrators can enable LDAP over SSL (LDAPS) by installing a properly formatted certificate from either a Microsoft certification authority (CA) or a non-Microsoft CA, according to the guidelines in Microsoft Knowledge Base Article 321051.

Is LDAP over SSL available by default? 
No. Before an LDAP server can participate in an SSL session, the administrator must have obtained a digital certificate and installed it on the server. Unless this has been done, LDAP over SSL is not available.

What might an attacker use the vulnerability to do? 
An attacker who successfully exploited this vulnerability could run arbitrary code. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

How could an attacker exploit the vulnerability? 
An attacker could try to exploit the vulnerability by sending a specially crafted LDAP packet to a Microsoft Windows 2000 Domain Controller. Any anonymous user with access to the target network could deliver a specially crafted network packet to the affected system in order to exploit this vulnerability.

What systems are primarily at risk from the vulnerability? 
LDAP is a requirement for Active Directory. Any Microsoft Windows 2000 Server that is running as an Active Directory Server is affected by this vulnerability.

What does the update do? 
The update addresses the vulnerability by correctly allocating memory for specially crafted client LDAP requests.

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.

Update Information

Detection and Deployment Tools and Guidance

Manage the software and security updates you need to deploy to the servers, desktop, and mobile systems in your organization. For more information see the TechNet Update Management Center. The Microsoft TechNet Security Web site provides additional information about security in Microsoft products.

Security updates are available from Microsoft Update, Windows Update, and Office Update. Security updates are also available from the Microsoft Download Center. You can find them most easily by doing a keyword search for "security update."

Finally, security updates can be downloaded from the Microsoft Update Catalog. The Microsoft Update Catalog provides a searchable catalog of content made available through Windows Update and Microsoft Update, including security updates, drivers and service packs. By searching using the security bulletin number (such as, “MS07-036”), you can add all of the applicable updates to your basket (including different languages for an update), and download to the folder of your choosing. For more information about the Microsoft Update Catalog, see the Microsoft Update Catalog FAQ.

Detection and Deployment Guidance

Microsoft has provided detection and deployment guidance for this month’s security updates. This guidance will also help IT professionals understand how they can use various tools to help deploy the security update, such as Windows Update, Microsoft Update, Office Update, the Microsoft Baseline Security Analyzer (MBSA), the Office Detection Tool, Microsoft Systems Management Server (SMS), and the Extended Security Update Inventory Tool. For more information, see Microsoft Knowledge Base Article 910723.

Microsoft Baseline Security Analyzer

Microsoft Baseline Security Analyzer (MBSA) allows administrators to scan local and remote systems for missing security updates as well as common security misconfigurations. For more information about MBSA, visit Microsoft Baseline Security Analyzer.

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

For more information about MBSA 2.1, see MBSA 2.1 Frequently Asked Questions.

Windows Server Update Services

By using Windows Server Update Services (WSUS), administrators can 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. For more information about how to deploy this security update using Windows Server Update Services, visit the Windows Server Update Services Web site.

Systems Management Server

The following table provides the SMS detection and deployment summary for this security update.

For SMS 2.0 and SMS 2003, the SMS SUS Feature Pack (SUSFP), which includes the Security Update Inventory Tool (SUIT), can be used by SMS to detect security updates. See also Downloads for Systems Management Server 2.0.

For SMS 2003, the SMS 2003 Inventory Tool for Microsoft Updates (ITMU) 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 ITMU, see SMS 2003 Inventory Tool for Microsoft Updates. SMS 2003 can also use the Microsoft Office Inventory Tool to detect required updates for Microsoft Office applications. For more information about the Office Inventory Tool and other scanning tools, see SMS 2003 Software Update Scanning Tools. See also Downloads for Systems Management Server 2003.

System Center Configuration Manager 2007 uses WSUS 3.0 for detection of updates. For more information about Configuration Manager 2007 Software Update Management, visit System Center Configuration Manager 2007.

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

For more detailed information, see Microsoft Knowledge Base Article 910723: Summary list of monthly detection and deployment guidance articles.

Security Update Deployment

Affected Software

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

Windows 2000 Server with Active Directory

Reference Table

The following table contains the security update information for this software. You can find additional information in the subsection, Deployment Information, in this section.

Deployment Information

Installing the Update

When you install this security update, the installer checks whether one or more of the files that are being updated on your system have previously been updated by a Microsoft hotfix.

If you have previously installed a hotfix to update one of these files, the installer copies the RTMQFE, SP1QFE, or SP2QFE files to your system. Otherwise, the installer copies the RTMGDR, SP1GDR, or SP2GDR files to your system. Security updates may not contain all variations of these files. For more information about this behavior, see Microsoft Knowledge Base Article 824994.

For more information about the 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.

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.

Removing the Update

This security update supports the following setup switches.

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 may be able to use the Microsoft Baseline Security Analyzer (MBSA) tool. See the section, Detection and Deployment Tools and Guidance, earlier in this bulletin for more information.

• File Version Verification

  Because there are several editions of Microsoft Windows, the following steps may be different on your system. 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 edition of the operating system, or the programs that are installed on your system, 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 system 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 registry keys listed in the Reference Table in this section.

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

Other Information

Acknowledgments

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

• Paul Miseiko of nCircle for reporting the Active Directory Overflow Vulnerability (CVE-2008-4023)

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 (October 14, 2008): Bulletin published.
• V1.1 (October 15, 2008): Updated the Non-Affected Software table.

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