__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Center ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Microsoft Unchecked Buffer in Windows Shell [Microsoft Security Bulletin MS02-014] March 12, 2002 18:00 GMT Number M-055 ______________________________________________________________________________ PROBLEM: An unchecked buffer exists in one of the functions that helps to locate incompletely removed applications on the system. PLATFORM: Microsoft Windows 98 Microsoft Windows 98 Second Edition Microsoft Windows NT 4.0 Microsoft Windows NT 4.0 Terminal Server Edition Microsoft Windows 2000 DAMAGE: A successful attack would have the affect of either causing the Windows Shell to crash, or causing code to run with the user's permissions. SOLUTION: Apply the patch provided by vendor. ______________________________________________________________________________ VULNERABILITY The risk is LOW. The exploit of this vulnerability would allow ASSESSMENT: the code to run in the security context of the user rather than the system. ______________________________________________________________________________ LINKS: CIAC BULLETIN: http://www.ciac.org/ciac/bulletins/m-055.shtml ORIGINAL BULLETIN: http://www.microsoft.com/technet/security/bulletin/MS02-014.asp PATCHES: Windows 98 http://www.microsoft.com/Downloads/Release.asp?ReleaseID=37015 Windows NT 4.0 http://www.microsoft.com/downloads/release.asp?ReleaseID=36867 Windows NT 4.0 with Active Desktop http://www.microsoft.com/Downloads/Release.asp?ReleaseID=37015 Windows NT 4.0 Terminal Server Edition http://www.microsoft.com/downloads/release.asp?ReleaseID=36869 Windows NT 2000 http://www.microsoft.com/downloads/release.asp?ReleaseID=36880 ______________________________________________________________________________ [***** Start Microsoft Security Bulletin MS02-014 *****] Unchecked Buffer in Windows Shell Could Lead to Code Execution Originally posted: March 07, 2002 Summary Who should read this bulletin: Users of Microsoft® Windows® 98, 98SE, Windows NT® 4.0, Windows 2000 Impact of vulnerability: Run code of an attacker's choice Maximum Severity Rating: Moderate Recommendation: Customers should apply the patch Affected Software: - Microsoft Windows 98 - Microsoft Windows 98 Second Edition - Microsoft Windows NT 4.0 - Microsoft Windows NT 4.0 Terminal Server Edition - Microsoft Windows 2000 Technical description: The Windows Shell is responsible for providing the basic framework of the Windows user interface experience. It is most familiar to users as the Windows Desktop, but also provides a variety of other functions to help define the user's computing session, including organizing files and folders, and providing the means to start applications. An unchecked buffer exists in one of the functions that helps to locate incompletely removed applications on the system. A security vulnerability results because it is possible for a malicious user to mount a buffer overrun attack and attempt to exploit this flaw. A successful attack would have the affect of either causing the Windows Shell to crash, or causing code to run in the user's context. By default, this is not remotely exploitable. However, under very unusual conditions, it could be exploited via a web page. Specifically, if the user has installed, then uninstalled an application with custom URL handlers, and the application's uninstall routine failed to correctly remove the application completely, an attacker could attempt to mount an attack by constructing an HTML web page that seeks to overrun the buffer. Such a web page could be delivered either by posting it on a web site or sending it by email. Mitigating factors: - In a default installation, this vulnerability is not remotely exploitable and could only be exploited by introducing hostile code to the system. - The vulnerability could be remotely exploited only if the user has installed and uninstalled software which implements customer URL handlers and the software's uninstall routine failed to completely remove the application from the system. - Outlook 98 and 2000 (after installing the Outlook Email Security Update), Outlook 2002, and Outlook Express 6 all open HTML mail in the Restricted Sites Zone. As a result, customers using these products would not be at risk from email-borne attacks. - The buffer overrun would allow code to run in the security context of the user rather than the system. The specific privileges the attacker could gain through this vulnerability would therefore depend on the privileges accorded to the user. Vulnerability identifier: CAN-2001-0070 Patch availability Download locations for this patch Windows 98 http://www.microsoft.com/Downloads/Release.asp?ReleaseID=37015 Windows NT 4.0 http://www.microsoft.com/downloads/release.asp?ReleaseID=36867 Windows NT 4.0 with Active Desktop http://www.microsoft.com/Downloads/Release.asp?ReleaseID=37015 Windows NT 4.0 Terminal Server Edition http://www.microsoft.com/downloads/release.asp?ReleaseID=36869 Windows NT 2000 http://www.microsoft.com/downloads/release.asp?ReleaseID=36880 Additional information about this patch Installation platforms: The Windows 98 patch can be installed on system running Windows 98 and Windows 98SE. The Windows NT 4.0 patch can be installed on systems running Service Pack 6a. The Windows NT 4.0 Terminal Server Edition patch can be installed on systems running Windows NT 4.0 TSE Service Pack 6. The Windows 2000 patch can be installed on systems running Windows 2000 Service Pack 2. Inclusion in future service packs: The fix for this issue will be included in Windows 2000 Service Pack 3 Reboot needed: Yes Superseded patches: None. Verifying patch installation: Windows 98 and 98 SE: To verify that the patch has been installed on the machine, select Start, then Run, then run the QFECheck utility. If the patch is installed, "Windows 98 Q313829 Update" will be listed among the installed patches. To verify the individual files, use the file manifest provided in Knowledge Base article Q313829. Windows NT 4.0 Service Pack 6a: To verify that the patch has been installed on the machine, confirm that the following registry key has been created on the machine: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Hotfix\Q313829 To verify the individual files, consult the file manifest in Knowledge Base article Q313829 Windows NT 4.0 Service Pack 6a with Active Desktop: To verify that the patch has been installed on the machine, confirm that the following registry key has been created on the machine: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Hotfix\Q313829. To verify the individual files, consult the file manifest in Knowledge Base article Q313829 Windows NT 4.0 Terminal Server Edition Service Pack 6: To verify that the patch has been installed on the machine, confirm that the following registry key has been created on the machine: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Hotfix\Q313829. To verify the individual files, consult the file manifest in Knowledge Base article Q313829 Windows 2000 Service Pack 2: To verify that the patch has been installed on the machine, confirm that the following registry key has been created on the machine: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows 2000\SP3\Q313829. To verify the individual files, use the date/time and version information provided in the following registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows 2000\SP3\Q313829\Filelist Caveats: None Localization: Localized versions of this patch are currently available at the locations listed above in "Patch Availability". Obtaining other security patches: Patches for other security issues are available from the following locations: Security patches are available from the Microsoft Download Center, and can be most easily found by doing a keyword search for "security_patch". Patches for consumer platforms are available from the WindowsUpdate web site. All patches available via WindowsUpdate also are available in a redistributable form from the WindowsUpdate Corporate site. Other information: Acknowledgments Microsoft thanks eEye Digital Security (http://www.eeye.com) for reporting this issue to us and working with us to protect customers. Support: Microsoft Knowledge Base article Q313829 discusses this issue and will be available approximately 24 hours after the release of this bulletin. Knowledge Base articles can be found on the Microsoft Online Support web site. Technical support is available from Microsoft Product Support Services. There is no charge for support calls associated with security patches. Security Resources: The Microsoft TechNet Security Web Site provides additional information about security in Microsoft products. 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 (March 07, 2002): Bulletin Created. [***** End Microsoft Security Bulletin MS02-014 *****] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of Microsoft Corporation for the information contained in this bulletin. _______________________________________________________________________________ CIAC, the Computer Incident Advisory Center, is the computer security incident response team for the U.S. Department of Energy (DOE) and the emergency backup response team for the National Institutes of Health (NIH). CIAC is located at the Lawrence Livermore National Laboratory in Livermore, California. CIAC is also a founding member of FIRST, the Forum of Incident Response and Security Teams, a global organization established to foster cooperation and coordination among computer security teams worldwide. CIAC services are available to DOE, DOE contractors, and the NIH. CIAC can be contacted at: Voice: +1 925-422-8193 (7x24) FAX: +1 925-423-8002 STU-III: +1 925-423-2604 E-mail: ciac@ciac.org Previous CIAC notices, anti-virus software, and other information are available from the CIAC Computer Security Archive. World Wide Web: http://www.ciac.org/ Anonymous FTP: ftp.ciac.org PLEASE NOTE: Many users outside of the DOE, ESnet, and NIH computing communities receive CIAC bulletins. If you are not part of these communities, please contact your agency's response team to report incidents. Your agency's team will coordinate with CIAC. The Forum of Incident Response and Security Teams (FIRST) is a world-wide organization. A list of FIRST member organizations and their constituencies can be obtained via WWW at http://www.first.org/. This document was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor the University of California nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation or favoring by the United States Government or the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or the University of California, and shall not be used for advertising or product endorsement purposes. 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