Microsoft Security Bulletin MS11-051 - Important

Vulnerability in Active Directory Certificate Services Web Enrollment Could Allow Elevation of Privilege (2518295)

Published: Tuesday, June 14, 2011 | Updated: Wednesday, June 15, 2011

Version: 1.1

General Information

Executive Summary

This security update resolves a privately reported vulnerability in Active Directory Certificate Services Web Enrollment. The vulnerability is a cross-site scripting (XSS) vulnerability that could allow elevation of privilege, enabling an attacker to execute arbitrary commands on the site in the context of the target user. An attacker who successfully exploited this vulnerability would need to send a specially crafted link and convince a user to click the link. In all cases, however, an attacker would have no way to force a user to visit the Web site. Instead, an attacker would have to persuade a user to visit the Web site, typically by getting them to click a link in an e-mail message or Instant Messenger message that takes the user to the vulnerable Web site.

This security update is rated Important for all supported editions, except Itanium, of Windows Server 2003, Windows Server 2008, and Windows Server 2008 R2. For more information, see the subsection, Affected and Non-Affected Software, in this section.

The security update addresses the vulnerability by correcting the manner in which the Active Directory Certificate Services Web Enrollment site validates input parameters. 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. The majority of customers have automatic updating enabled and will not need to take any action because this security update will be downloaded and installed automatically. Customers who have not enabled automatic updating need to check for updates and install this update manually. For information about specific configuration options in automatic updating, see Microsoft Knowledge Base Article 294871.

For administrators and enterprise installations, or end users who want to install this security update manually, Microsoft recommends that customers apply the update at the earliest opportunity using update management software, or by checking for updates using the Microsoft Update service.

See also the section, Detection and Deployment Tools and Guidance, later in this bulletin.

Known Issues. Microsoft Knowledge Base Article 2518295 documents the currently known issues that customers may experience when installing this security update. The article also documents recommended solutions for these issues.

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 Server 2003 Service Pack 2	Elevation of Privilege	Important	None
Windows Server 2003 x64 Edition Service Pack 2	Elevation of Privilege	Important	None
Windows Server 2008 for 32-bit Systems and Windows Server 2008 for 32-bit Systems Service Pack 2**	Elevation of Privilege	Important	None
Windows Server 2008 for x64-based Systems and Windows Server 2008 for x64-based Systems Service Pack 2**	Elevation of Privilege	Important	None
Windows Server 2008 R2 for x64-based Systems and Windows Server 2008 R2 for x64-based Systems Service Pack 1**	Elevation of Privilege	Important	None

**Server Core installation not affected. The vulnerabilities addressed by this update do not affect supported editions of Windows Server 2008 or Windows Server 2008 R2 as indicated, when installed using the Server Core installation option. For more information on this installation option, see the TechNet articles, Managing a Server Core Installation and Servicing a Server Core Installation. Note that the Server Core installation option does not apply to certain editions of Windows Server 2008 and Windows Server 2008 R2; see Compare Server Core Installation Options.

Non-Affected Software

Operating System
Windows XP Service Pack 3
Windows XP Professional x64 Edition Service Pack 2
Windows Server 2003 with SP2 for Itanium-based Systems
Windows Vista Service Pack 1 and Windows Vista Service Pack 2
Windows Vista x64 Edition Service Pack 1 and Windows Vista x64 Edition Service Pack 2
Windows Server 2008 for Itanium-based Systems and Windows Server 2008 for Itanium-based Systems Service Pack 2
Windows 7 for 32-bit Systems and Windows 7 for 32-bit Systems Service Pack 1
Windows 7 for x64-based Systems and Windows 7 for x64-based Systems Service Pack 1
Windows Server 2008 R2 for Itanium-based Systems and Windows Server 2008 R2 for Itanium-based Systems Service Pack 1

Frequently Asked Questions (FAQ) Related to This Security Update

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 Server systems not configured in the Active Directory Certificate Services Web Enrollment role are not affected and will not receive this update.

I have customized my web enrollment ASP pages. Do I need to be concerned with the known issues listed in Microsoft Knowledge Base Article 2518295?
Yes, Microsoft recommends that customers who have edited their Web enrollment ASP pages should visit Microsoft Knowledge Base Article 2518295 for important information about known issues that may apply to their systems.

Where are the file information details?
Refer to the reference tables in the Security Update Deployment section for the location of the file information details.

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. For more information about the product lifecycle, visit the Microsoft Support Lifecycle Web site.

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. To determine the support lifecycle for your software release, see Select a Product for Lifecycle Information. For more information about service packs for these software releases, see Lifecycle Supported Service Packs.

Customers who require custom support for older software 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 in the Contact Information list, 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 Microsoft Support Lifecycle Policy FAQ.

Vulnerability Information

Severity Ratings and Vulnerability Identifiers

Vulnerability Severity Rating and Maximum Security Impact by Affected Software
Affected Software	Active Directory Certificate Services Vulnerability - CVE-2011-1264	Aggregate Severity Rating
Windows Server 2003 Service Pack 2	Important Elevation of Privilege	Important
Windows Server 2003 x64 Edition Service Pack 2	Important Elevation of Privilege	Important
Windows Server 2008 for 32-bit Systems and Windows Server 2008 for 32-bit Systems Service Pack 2**	Important Elevation of Privilege	Important
Windows Server 2008 for x64-based Systems and Windows Server 2008 for x64-based Systems Service Pack 2**	Important Elevation of Privilege	Important
Windows Server 2008 R2 for x64-based Systems and Windows Server 2008 R2 for x64-based Systems Service Pack 1**	Important Elevation of Privilege	Important

Active Directory Certificate Services Vulnerability - CVE-2011-1264

A reflected XSS vulnerability exists in Active Directory Certificate Services Web Enrollment that could allow an attacker to inject a client-side script into the user's instance of Internet Explorer. The script could spoof content, disclose information, or take any action that the user could take on the site on behalf of the targeted user.

To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2011-1264.

Mitigating Factors for Active Directory Certificate Services Vulnerability - CVE-2011-1264

Workarounds for Active Directory Certificate Services Vulnerability - CVE-2011-1264

FAQ for Active Directory Certificate Services Vulnerability - CVE-2011-1264

What is the scope of the vulnerability?
This is a reflected XSS vulnerability that could allow an elevation of privilege.

What causes the vulnerability?
The vulnerability is caused by improper input validation of a request parameter on an Active Directory Certificate Services Web Enrollment site.

What is cross-site scripting (XSS)?
Cross-site scripting (XSS) is a class of security vulnerability that can enable an attacker to inject script into the response to a Web page request. This script is then run by the requesting application, often times a Web browser. The script could then spoof content, disclose information, or take any action that the user could take on the affected Web site, on behalf of the targeted user.

What is the component affected by the vulnerability?
The affected component is Active Directory Certificate Services Web Enrollment.

What might an attacker use the vulnerability to do?
An attacker who successfully exploited this vulnerability could inject a client-side script into the user's instance of Internet Explorer. The script could spoof content, disclose information, or take any action that the user could take on the site on behalf of the targeted user.

How could an attacker exploit the vulnerability?
In an e-mail attack scenario, an attacker could exploit the vulnerability by sending a specially crafted link to the user and convincing the user to click the link.

What systems are primarily at risk from the vulnerability?
Servers running the Active Directory Certificate Services Web Enrollment role are primarily at risk. Servers not running this specific role are not at risk.

What does the update do?
The update addresses the vulnerability by correcting the manner in which the Active Directory Certificate Services Web Enrollment site validates input parameters.

When this security bulletin was issued, had this vulnerability been publicly disclosed?
No. Microsoft received information about this vulnerability through coordinated vulnerability 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 when this security bulletin was originally issued.

Update Information

Detection and Deployment Tools and Guidance

Security Central

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 and Windows 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 provides detection and deployment guidance for security updates. This guidance contains recommendations and information that can help IT professionals understand how to use various tools for detection and deployment of security updates. For more information, see Microsoft Knowledge Base Article 961747.

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.

Software	MBSA
Windows Server 2003 Service Pack 2	Yes
Windows Server 2003 x64 Edition Service Pack 2	Yes
Windows Server 2008 for 32-bit Systems and Windows Server 2008 for 32-bit Systems Service Pack 2	Yes
Windows Server 2008 for x64-based Systems and Windows Server 2008 for x64-based Systems Service Pack 2	Yes
Windows Server 2008 R2 for x64-based Systems and Windows Server 2008 R2 for x64-based Systems Service Pack 1	Yes

Note For customers using legacy software not supported by the latest release of MBSA, Microsoft Update, and Windows Server Update Services, please visit Microsoft Baseline Security Analyzer and reference the Legacy Product Support section on how to create comprehensive security update detection with legacy tools.

Windows Server Update Services

Windows Server Update Services (WSUS) enables information technology administrators to deploy the latest Microsoft product updates to computers that are running the Windows operating system. For more information about how to deploy security updates using Windows Server Update Services, see the TechNet article, Windows Server Update Services.

Systems Management Server

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

Software	SMS 2003 with ITMU	Configuration Manager 2007
Windows Server 2003 Service Pack 2	Yes	Yes
Windows Server 2003 x64 Edition Service Pack 2	Yes	Yes
Windows Server 2008 for 32-bit Systems and Windows Server 2008 for 32-bit Systems Service Pack 2	Yes	Yes
Windows Server 2008 for x64-based Systems and Windows Server 2008 for x64-based Systems Service Pack 2	Yes	Yes
Windows Server 2008 R2 for x64-based Systems and Windows Server 2008 R2 for x64-based Systems Service Pack 1	Yes	Yes

Note Microsoft discontinued support for SMS 2.0 on April 12, 2011. For SMS 2003, Microsoft also discontinued support for the Security Update Inventory Tool (SUIT) on April 12, 2011. Customers are encouraged to upgrade to System Center Configuration Manager 2007. For customers remaining on SMS 2003 Service Pack 3, the Inventory Tool for Microsoft Updates (ITMU) is also an option.

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. For more information about SMS 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.

Update Compatibility Evaluator and Application Compatibility Toolkit

Updates often write to the same files and registry settings required for your applications to run. This can trigger incompatibilities and increase the time it takes to deploy security updates. You can streamline testing and validating Windows updates against installed applications with the Update Compatibility Evaluator components included with Application Compatibility Toolkit.

The Application Compatibility Toolkit (ACT) contains the necessary tools and documentation to evaluate and mitigate application compatibility issues before deploying Microsoft Windows Vista, a Windows Update, a Microsoft Security Update, or a new version of Windows Internet Explorer in your environment.

Security Update Deployment


Inclusion in Future Service Packs	The update for this issue will be included in a future service pack or update rollup
Deployment
Installing without user intervention	For all supported 32-bit editions of Windows Server 2003: WindowsServer2003-KB2518295-x86-enu.exe /quiet
	For all supported x64-based editions of Windows Server 2003: WindowsServer2003.WindowsXP-KB2518295-x64-enu.exe /quiet
Installing without restarting	For all supported 32-bit editions of Windows Server 2003: WindowsServer2003-KB2518295-x86-enu.exe /norestart
	For all supported x64-based editions of Windows Server 2003: WindowsServer2003.WindowsXP-KB2518295-x64-enu.exe /norestart
Update log file	KB2518295.log
Further information	See the subsection, Detection and Deployment Tools and Guidance
Restart Requirement
Restart required?	In some cases, this update does not require a restart. If the required files are being used, this update will require a restart. If this behavior occurs, a message appears that advises you to restart. To help reduce the chance that a restart will be required, stop all affected services and close all applications that may use the affected files prior to installing the security update. For more information about the reasons why you may be prompted to restart, see Microsoft Knowledge Base Article 887012.
HotPatching	This security update does not support HotPatching. For more information about HotPatching, see Microsoft Knowledge Base Article 897341.
Removal Information	Use Add or Remove Programs tool in Control Panel or the Spuninst.exe utility located in the %Windir%\$NTUninstallKB2518295$\Spuninst folder
File Information	See Microsoft Knowledge Base Article 2518295
Registry Key Verification	HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows Server 2003\SP3\KB2518295\Filelist

Supported Security Update Installation Switches
Switch	Description
/help	Displays the command-line options.
Setup Modes
/passive	Unattended Setup mode. No user interaction is required, but installation status is displayed. If a restart is required at the end of Setup, a dialog box will be presented to the user with a timer warning that the computer will restart in 30 seconds.
/quiet	Quiet mode. This is the same as unattended mode, but no status or error messages are displayed.
Restart Options
/norestart	Does not restart when installation has completed.
/forcerestart	Restarts the computer after installation and force other applications to close at shutdown without saving open files first.
/warnrestart[:x]	Presents a dialog box with a timer warning the user that the computer will restart in x seconds. (The default setting is 30 seconds.) Intended for use with the /quiet switch or the /passive switch.
/promptrestart	Displays a dialog box prompting the local user to allow a restart.
Special Options
/overwriteoem	Overwrites OEM files without prompting.
/nobackup	Does not back up files needed for uninstall.
/forceappsclose	Forces other programs to close when the computer shuts down.
/log:path	Allows the redirection of installation log files.
/integrate:path	Integrates the update into the Windows source files. These files are located at the path that is specified in the switch.
/extract[:path]	Extracts files without starting the Setup program.
/ER	Enables extended error reporting.
/verbose	Enables verbose logging. During installation, creates %Windir%\CabBuild.log. This log details the files that are copied. Using this switch may cause the installation to proceed more slowly.

Supported Spuninst.exe Switches
Switch	Description
/help	Displays the command-line options.
Setup Modes
/passive	Unattended Setup mode. No user interaction is required, but installation status is displayed. If a restart is required at the end of Setup, a dialog box will be presented to the user with a timer warning that the computer will restart in 30 seconds.
/quiet	Quiet mode. This is the same as unattended mode, but no status or error messages are displayed.
Restart Options
/norestart	Does not restart when installation has completed.
/forcerestart	Restarts the computer after installation and force other applications to close at shutdown without saving open files first.
/warnrestart[:x]	Presents a dialog box with a timer warning the user that the computer will restart in x seconds. (The default setting is 30 seconds.) Intended for use with the /quiet switch or the /passive switch.
/promptrestart	Displays a dialog box prompting the local user to allow a restart.
Special Options
/forceappsclose	Forces other programs to close when the computer shuts down.
/log:path	Allows the redirection of installation log files.


Inclusion in Future Service Packs	The update for this issue will be included in a future service pack or update rollup
Deployment
Installing without user intervention	For all supported 32-bit editions of Windows Server 2008: Windows6.0-KB2518295-x86.msu /quiet
	For all supported x64-based editions of Windows Server 2008: Windows6.0-KB2518295-x64.msu /quiet
Installing without restarting	For all supported 32-bit editions of Windows Server 2008: Windows6.0-KB2518295-x86.msu /quiet /norestart
	For all supported x64-based editions of Windows Server 2008: Windows6.0-KB2518295-x64.msu /quiet /norestart
Further information	See the subsection, Detection and Deployment Tools and Guidance
Restart Requirement
Restart required?	This update does not require a restart. The installer stops the required services, applies the update, and then restarts the services. However, if the required services cannot be stopped for any reason, or if required files are being used, this update will require a restart. If this behavior occurs, a message appears that advises you to restart.
HotPatching	Not applicable.
Removal Information	WUSA.exe does not support uninstall of updates. To uninstall an update installed by WUSA, click Control Panel, and then click Security. Under Windows Update, click View installed updates and select from the list of updates.
File Information	See Microsoft Knowledge Base Article 2518295
Registry Key Verification	Note A registry key does not exist to validate the presence of this update.

Supported Security Update Installation Switches
Switch	Description
/?, /h, /help	Displays help on supported switches.
/quiet	Suppresses the display of status or error messages.
/norestart	When combined with /quiet, the system will not be restarted after installation even if a restart is required to complete installation.


Inclusion in Future Service Packs	The update for this issue will be included in a future service pack or update rollup
Deployment
Installing without user intervention	For all supported x64-based editions of Windows Server 2008 R2: Windows6.1-KB2518295-x64.msu /quiet
Installing without restarting	For all supported x64-based editions of Windows Server 2008 R2: Windows6.1-KB2518295-x64.msu /quiet /norestart
Further information	See the subsection, Detection and Deployment Tools and Guidance
Restart Requirement
Restart required?	This update does not require a restart. The installer stops the required services, applies the update, and then restarts the services. However, if the required services cannot be stopped for any reason, or if required files are being used, this update will require a restart. If this behavior occurs, a message appears that advises you to restart.
HotPatching	Not applicable.
Removal Information	To uninstall an update installed by WUSA, use the /Uninstall setup switch or click Control Panel, click System and Security, and then under Windows Update, click View installed updates and select from the list of updates.
File Information	See Microsoft Knowledge Base Article 2518295
Registry Key Verification	Note A registry key does not exist to validate the presence of this update.

Supported Security Update Installation Switches
Switch	Description
/?, /h, /help	Displays help on supported switches.
/quiet	Suppresses the display of status or error messages.
/norestart	When combined with /quiet, the system will not be restarted after installation even if a restart is required to complete installation.
/warnrestart:<seconds>	When combined with /quiet, the installer will warn the user before initiating restart.
/promptrestart	When combined with /quiet, the installer will prompt before initiating restart.
/forcerestart	When combined with /quiet, the installer will forcefully close applications and initiate restart.
/log:<file name>	Enables logging to specified file.
/extract:<destination>	Extracts the package contents to the destination folder.
/uninstall /kb:<KB Number>	Uninstalls the security update.

Other Information

Acknowledgments

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

Ruggero Strabla, Emaze Networks; Saipem Security Team for reporting the Active Directory Certificate Services Vulnerability (CVE-2011-1264)

Microsoft Active Protections Program (MAPP)

To improve security protections for customers, Microsoft provides vulnerability information to major security software providers in advance of each monthly security update release. Security software providers can then use this vulnerability information to provide updated protections to customers via their security software or devices, such as antivirus, network-based intrusion detection systems, or host-based intrusion prevention systems. To determine whether active protections are available from security software providers, please visit the active protections Web sites provided by program partners, listed in Microsoft Active Protections Program (MAPP) Partners.

Support

Customers in the U.S. and Canada can receive technical support from Security Support or 1-866-PCSAFETY. There is no charge for support calls that are associated with security updates. For more information about available support options, see Microsoft Help and Support.
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 14, 2011): Bulletin published.
V1.1 (June 15, 2011): Clarified the XSS Filter mitigation.

Microsoft Security Bulletin MS11-051 - Important

Vulnerability in Active Directory Certificate Services Web Enrollment Could Allow Elevation of Privilege (2518295)

General Information

Executive Summary

Affected and Non-Affected Software

Frequently Asked Questions (FAQ) Related to This Security Update

Vulnerability Information

Severity Ratings and Vulnerability Identifiers

Active Directory Certificate Services Vulnerability - CVE-2011-1264

Mitigating Factors for Active Directory Certificate Services Vulnerability - CVE-2011-1264

Workarounds for Active Directory Certificate Services Vulnerability - CVE-2011-1264

FAQ for Active Directory Certificate Services Vulnerability - CVE-2011-1264

Update Information

Detection and Deployment Tools and Guidance

Security Update Deployment

Windows Server 2003 (all editions)

Deployment Information

Windows Server 2008 (all editions)

Deployment Information

Windows Server 2008 R2 (all editions)

Deployment Information

Other Information

Acknowledgments

Microsoft Active Protections Program (MAPP)

Support

Disclaimer

Revisions