__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Center ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Microsoft Internet Explorer Vulnerabilities [Microsoft Security Bulletin MS02-015] March 29, 2002 19:00 GMT Number M-063 ______________________________________________________________________________ PROBLEM: Two vulnerabilities have been identified in Microsoft Internet Explorer (IE). The first vulnerability allows cookie-based script execution and the second vulnerability allows local executable invocation via object tags. PLATFORM: Microsoft Internet Explorer 5.01 Microsoft Internet Explorer 5.5 Microsoft Internet Explorer 6.0 DAMAGE: (1) An attacker could place a script in a cookie that would be saved to the user's hard disk. When the cookie was opened by the site the script would then run in the Local Computer zone. (2) A vulnerability in the handling of object tags may allow an attacker to invoke an executable already present on the user's machine. SOLUTION: Apply the patch provided by vendor. ______________________________________________________________________________ VULNERABILITY The risk is MEDIUM. (1) For the cookie-based script execution, ASSESSMENT: the script would run with the same rights as the user. (2) For local executable invocation via object tags, an attacker could only execute a file on the victim's local machine. ______________________________________________________________________________ LINKS: CIAC BULLETIN: http://www.ciac.org/ciac/bulletins/m-063.shtml ORIGINAL BULLETIN: http://www.microsoft.com/technet/treeview/default.asp?url=/technet/security/bulletin/MS02-015.asp ______________________________________________________________________________ [***** Start Microsoft Security Bulletin MS02-015 *****] Microsoft Security Bulletin MS02-015 28 March 2002 Cumulative Patch for Internet Explorer Originally posted: March 28, 2002 Summary Who should read this bulletin: Customers using Microsoft® Internet Explorer Impact of vulnerability: Two vulnerabilities, the most serious of which would allow script to run in the Local Computer Zone. Maximum Severity Rating: Critical Recommendation: Consumers using the affected version of IE should install the patch immediately. Affected Software: Microsoft Internet Explorer 5.01 Microsoft Internet Explorer 5.5 Microsoft Internet Explorer 6.0 Technical details Technical description: This is a cumulative patch that includes the functionality of all previously released patches for IE 5.01, 5.5 and IE 6. In addition, it eliminates the following two newly discovered vulnerabilities: A vulnerability in the zone determination function that could allow a script embedded in a cookie to be run in the Local Computer zone. While HTML scripts can be stored in cookies, they should be handled in the same zone as the hosting site associated with them, in most cases the Internet zone. An attacker could place script in a cookie that would be saved to the user’s hard disk. When the cookie was opened by the site the script would then run in the Local Computer zone, allowing it to run with fewer restrictions than it would otherwise have. A vulnerability in the handling of object tags that could allow an attacker to invoke an executable already present on the user’s machine. A malicious user could create HTML web page that includes this object tag and cause a local program to run on the victim’s machine. Mitigating factors: Cookie-based Script Execution: The script would run with the same rights as the user. The specific privileges the attacker could gain through this vulnerability would therefore depend on the privileges accorded to the user. Any limitations on a user's account, such as those applied through Group Policies, would also limit the actions of any script executed by this vulnerability. Local Executable Invocation via Object tag: The vulnerability would not enable the attacker to pass any parameters to the program. Microsoft is not aware of any programs installed by default in any version of Windows that, when called with no parameters, could be used to compromise the system. An attacker could only execute a file on the victim’s local machine. The vulnerability could not be used to execute a program on a remote share or web site. The vulnerability would not provide any way for an attacker to put a program of his choice onto another user’s system. An attacker would need to know the name and location of any executable on the system to successfully invoke it. 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. Severity Rating: Cookie-based Script Execution: Internet Servers Intranet Servers Client Systems Internet Explorer 5.01 None None None Internet Explorer 5.5 Moderate Moderate Critical Internet Explorer 6.0 Moderate Moderate Critical Local Executable Invocation via Object tag: Internet Servers Intranet Servers Client Systems Internet Explorer 5.01 Moderate Moderate Moderate Internet Explorer 5.5 Moderate Moderate Moderate Internet Explorer 6.0 Moderate Moderate Moderate Aggregate severity of all vulnerabilities eliminated by patch: Internet Servers Intranet Servers Client Systems Internet Explorer 5.01 Critical Critical Critical Internet Explorer 5.5 Critical Critical Critical Internet Explorer 6.0 Critical Critical Critical 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. The Cookie-based script execution vulnerability cannot be exploited by email. The Local Executable Invocation vulnerability cannot pass parameters to the invoked executable. The aggregate severity includes the severity of vulnerabilities announced in previously released security bulletins. Vulnerability identifier: Cookie-based Script Execution: CAN-2002-0078 Local Executable Invocation via Object tag: CAN-2002-0077 Tested Versions: The following table indicates which of the currently supported versions of Internet Explorer are affected by the vulnerabilities. Versions of IE prior to 5.01 Service Pack 2 are no longer eligible for hotfix support. IE 5.01 SP2 is supported only via Windows® 2000 Service Packs and Security Roll-up Packages and on Windows NT® 4.0. IE 5.01 SP2 IE 5.5 SP1 IE 5.5 SP2 IE 6.0 Cookie-based Script Execution No Yes Yes Yes Local Executable Invocation via Object tag Yes Yes Yes Yes Patch availability Download locations for this patch http://www.microsoft.com/windows/ie/downloads/critical/Q319182/default.asp Additional information about this patch Installation platforms: The IE 5.01 patch can be applied to Windows 2000 Systems with Service Pack 2 or Windows NT 4.0 systems with Service Pack 6a. The IE 5.5 patch can be installed on systems running IE 5.5 Service Pack 1 or Service Pack 2. The IE 6.0 patch can be installed on system running IE 6.0 Gold. Inclusion in future service packs: The fixes for these issues will be included in IE 6.0 Service Pack 1. The fixes for the issues affecting IE 5.01 Service Pack 2 will be included in Windows 2000 Service Pack 3. Reboot needed: Yes Superseded patches: This patch supersedes the one provided in Microsoft Security Bulletin MS02-005, which is itself a cumulative patch. Verifying patch installation: To verify that the patch has been installed on the machine, open IE, select Help, then select About Internet Explorer and confirm that Q319182 is listed in the Update Versions field. To verify the individual files, use the patch manifest provided in Knowledge Base article Q319182. 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 web site. All patches available via WindowsUpdate also are available in a redistributable form from the WindowsUpdate Corporate site. Other information: Acknowledgments Microsoft thanks Andreas Sandblad, Sweden for reporting the Cookie-based Script Execution issue to us and working with us to protect customers. Support: Microsoft Knowledge Base article Q319182 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 28, 2002): Bulletin Created. [***** End Microsoft Security Bulletin MS02-015 *****] _______________________________________________________________________________ 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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