__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Unchecked Buffer in Microsoft Windows Shell Could Enable System Compromise [Microsoft Security Bulletin MS03-027] July 17, 2003 21:00 GMT Number N-120 ______________________________________________________________________________ PROBLEM: An unchecked buffer exists in one of the functions used by the Windows shell to extract custom attribute information from certain folders. A security vulnerability results because it is possible for a malicious user to construct an attack that could exploit this flaw and execute code on a user’s system. PLATFORM: Microsoft Windows XP DAMAGE: A successful attack could have the effect of either causing the Windows shell to fail, or causing an attacker’s code to run on the user’s computer in the security context of the user. SOLUTION: Apply patch as stated in Microsoft's security bulletin. ______________________________________________________________________________ VULNERABILITY The risk is MEDIUM. In order to exploit this vulnerability, an ASSESSMENT: attacker needs to create a Desktop.ini file that contains corrupt attributes and host it on a network or Internet share. The attacker could then attempt to lure users to that share. ______________________________________________________________________________ LINKS: CIAC BULLETIN: http://www.ciac.org/ciac/bulletins/n-120.shtml ORIGINAL BULLETIN: http://www.microsoft.com/technet/treeview/ default.asp?url=/technet/security/bulletin/MS03-027.asp PATCHES: http://microsoft.com/downloads/ details.aspx?FamilyId=27D02AF5-A2E1-4E25-9D16-502886161A35 &displaylang=en http://microsoft.com/downloads/ details.aspx?FamilyId=4BA84E2B-49F9-4416-8745-51F03503AB7D &displaylang=en ______________________________________________________________________________ [***** Start Microsoft Security Bulletin MS03-027 *****] Microsoft Security Bulletin MS03-027 Unchecked Buffer in Windows Shell Could Enable System Compromise (821557) Originally posted: July 16, 2003 Updated: July 17, 2003 Summary Who should read this bulletin: Customers using Microsoft® Windows® XP Impact of vulnerability: Run code of an attacker's choice Maximum Severity Rating: Important Recommendation: Customers should install the patch at the earliest opportunity. End User Bulletin: An end-user version of this bulletin is available at: http://www.microsoft.com/security/security_bulletins/ms03-027.asp Affected Software: Affected Software: * Microsoft Windows XP Not affected Software: * Microsoft Windows Millennium Edition * Microsoft Windows NT® Server 4.0 * Microsoft Windows NT® 4.0, Terminal Server Edition * Microsoft Windows 2000 * Microsoft Windows Server 2003 Technical details 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. It 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 programs. An unchecked buffer exists in one of the functions used by the Windows shell to extract custom attribute information from certain folders. A security vulnerability results because it is possible for a malicious user to construct an attack that could exploit this flaw and execute code on the user’s system. An attacker could seek to exploit this vulnerability by creating a Desktop.ini file that contains a corrupt custom attribute, and then host it on a network share. If a user were to browse the shared folder where the file was stored, the vulnerability could then be exploited. A successful attack could have the effect of either causing the Windows shell to fail, or causing an attacker’s code to run on the user’s computer in the security context of the user. Mitigating factors: * In the case where an attacker’s code was executed, the code would run in the security context of the user. As a result, any limitations on the user's ability would also restrict the actions that an attacker's code could take. * An attacker could only seek to exploit this vulnerability by hosting a malicious file on a share. * This vulnerability only affects Windows XP Service Pack 1. Users running Windows XP Gold are not affected. Severity Rating: Windows XP Important The above assessment is based on the types of systems affected by the vulnerability, their typical deployment patterns, and the effect that exploiting the vulnerability would have on them. Vulnerability identifier: CAN-2003-0306 Tested Versions: Microsoft tested Windows Millennium, Windows NT Server 4.0, Windows NT 4.0 Terminal Server Edition, Windows 2000, Windows XP, and Windows Server 2003 to assess whether they are affected by this vulnerability. Previous versions are no longer supported, and may or may not be affected by this vulnerability. Patch availability Download locations for this patch * Microsoft Windows XP 32 bit Edition * Microsoft Windows XP 64 bit Edition Additional information about this patch Installation platforms: This patch can be installed on systems running Windows XP Service Pack 1. Inclusion in future service packs: The fix for this issue will be included Windows XP Service Pack 2. Reboot needed: Yes Patch can be uninstalled: Yes Superseded patches: None. Verifying patch installation: * 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 XP\SP2\KB821557 * 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 XP\SP2\KB821557\Filelist Caveats: None Localization: Localized versions of this patch are available at the locations discussed 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 site Other information: Support: * Microsoft Knowledge Base article 821557 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 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 (July 16, 2003): Bulletin published. * V1.1 (July 17, 2003): Corrected CVE Candidate number, added Windows XP Gold information to the Frequently Asked Questions section. [***** End Microsoft Security Bulletin MS03-027 *****] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of Microsoft Corporation for the information contained in this bulletin. _______________________________________________________________________________ CIAC, the Computer Incident Advisory Capability, 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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