__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Microsoft Cumulative Security Update for Internet Explorer [MS03-048] November 11, 2003 18:00 GMT Number O-021 ______________________________________________________________________________ PROBLEM: There are three new vulnerabilities: 1) A cross-domain security model problem could result in the execution of script in the My Computer zone. 2) The way zone information is passed to an XML object within Internet Explorer could allow an attacker to read local files on a user's system. 3) While performing a drag-and-drop operation during dynamic HTML (DHTML) events in Internet Explorer, files could be saved in a target locaiton on the user's system. SOFTWARE: Microsoft Windows 98 Microsoft Windows 98 Second Edition Microsoft Windows Millemmium Edition Microsoft Windows NT Workstation 4.0 Service Pack 6a Microsoft Windows NT Server 4.0 Service Pack 6a Microsoft Windows NT Server 4.0 Terminal Server Edition, Service Pack 6 Microsoft Windows 2000 Service Pack 2, Service Pack 3, Service Pack 4 Microsoft Windows XP, Microsoft Windows XP Service Pack 1 Microsoft Windows XP 64-Bit Edition Microsoft Windows XP 64-Bit Edition Version 2003 Microsoft Windows Server 2003 Microsoft Windows Server 2003, 64-Bit Edition Affected Components: Internet Explorer 6 Service Pack 1 Internet Explorer 6 Service Pack 1 (64-Bit Edition) Internet Explorer 6 Service Pack 1 for Windows Server 2003 Internet Explorer 6 Service Pack 1 for Windows Server 2003 (64-Bit Edition) Internet Explorer 6 Internet Explorer 5.5 Service Pack 2 Internet Explorer 5.01 Service Pack 4 Internet Explorer 5.01 Service Pack 3 Internet Explorer 5.01 Service Pack 2 DAMAGE: 1) An attacker having a malicious web site could access files on a user's system and run arbitrary code as the currently logged on user. 2) An attacker having a malicious web site could read local files that are in a known location on the user's system. 3) An attacker having a malicious web site could persuade a user to click a link causing code of the attacker's choice to be saved on the user's computer in a targeted location. SOLUTION: Install the security update immediately. NOTE--This is a cumulative update that includes all previous updates to Internet Explorer. This update replaces the one that is provided in MS03-040 (CIAC Bulletin O-002) which is itself a cumulative update. ______________________________________________________________________________ VULNERABILITY The risk is HIGH. An attacker would gain privileges up to and ASSESSMENT: including Administrator. ______________________________________________________________________________ LINKS: CIAC BULLETIN: http://www.ciac.org/ciac/bulletins/o-021.shtml ORIGINAL BULLETIN: Microsoft Security Bulletin MS03-048 http://www.microsoft.com/technet/treeview/default.asp?url= /technet/security/bulletin/MS03-048.asp CVE/CAN: http://www.cve.mitre.org/cgi-bin/cvename.cgi?name= CVE-2003-0814 CVE-2003-0815 CVE-2003-0816 CVE-2003-0817 CVE-2003-0823 ______________________________________________________________________________ [***** Start MS03-048 *****] Microsoft Security Bulletin MS03-048 Cumulative Security Update for Internet Explorer (824145) Issued: November 11, 2003 Version: 1.0 Summary Who Should Read This Document: Customers who have Microsoft® Internet Explorer® installed Impact of Vulnerability: Remote Code Execution Maximum Severity Rating: Critical Recommendation: Customers should install this security update immediately. Security Update Replacement: This update replaces the one that is provided in Microsoft Security Bulletin MS03-040, which is itself a cumulative update. Caveats: None Tested Software and Security Update Download Locations: Affected Software * Microsoft Windows 98 * Microsoft Windows 98 Second Edition * Microsoft Windows Millennium Edition * Microsoft Windows NT® Workstation 4.0 Service Pack 6a * Microsoft Windows NT Server 4.0 Service Pack 6a * Microsoft Windows NT Server 4.0 Terminal Server Edition, Service Pack 6 * Microsoft Windows 2000 Service Pack 2, Service Pack 3, Service Pack 4 * Microsoft Windows XP, Microsoft Windows XP Service Pack 1 * Microsoft Windows XP 64-Bit Edition * Microsoft Windows XP 64-Bit Edition Version 2003 * Microsoft Windows Server® 2003 * Microsoft Windows Server 2003, 64-Bit Edition Tested Microsoft Windows Components: Affected Components: * Internet Explorer 6 Service Pack 1: Download the update. * Internet Explorer 6 Service Pack 1 (64-Bit Edition): Download the update. * Internet Explorer 6 Service Pack 1 for Windows Server 2003: Download the update. * Internet Explorer 6 Service Pack 1 for Windows Server 2003 (64-Bit Edition): Download the update. * Internet Explorer 6: Download the update. * Internet Explorer 5.5 Service Pack 2: Download the update. * Internet Explorer 5.01 Service Pack 4: Download the update. * Internet Explorer 5.01 Service Pack 3: Download the update. * Internet Explorer 5.01 Service Pack 2: Download the update. The software listed above has been tested to determine if the versions are affected. Other versions are no longer supported and may or may not be affected. Technical Details Technical description: This is a cumulative update that includes the functionality of all the previously-released updates for Internet Explorer 5.01, Internet Explorer 5.5, and Internet Explorer 6.0. Additionally, it eliminates the following five newly-discovered vulnerabilities: * Three vulnerabilities that involve the cross-domain security model of Internet Explorer, which keeps windows of different domains from sharing information. These vulnerabilities could result in the execution of script in the My Computer zone. To exploit one of these vulnerabilities, an attacker would have to host a malicious Web site that contains a Web page that is designed to exploit the particular vulnerability and then persuade a user to view the Web page. The attacker could also create an HTML e-mail message that designed to exploit one of these vulnerabilities and persuade the user to view the HTML e-mail message. After the user has visited the malicious Web site or viewed the malicious HTML e-mail message an attacker who exploited one of these vulnerabilities could access information from other Web sites, access files on a user's system, and run arbitrary code on a user's system. This code would run in the security context of the currently logged on user. * A vulnerability that involves the way that zone information is passed to an XML object within Internet Explorer. This vulnerability could allow an attacker to read local files on a user's system. To exploit this vulnerability, an attacker would have to host a malicious Web site that contains a Web page that is designed to exploit the particular vulnerability and then persuade a user to view the Web page. The attacker could also create an HTML e-mail message that is designed to exploit this vulnerability and persuade the user to view the HTML e-mail message. After the user visits the malicious Web site or views the malicious HTML e-mail message, the user would then be prompted to download an HTML file. If the user accepts the download of this HTML file, an attacker could read local files that are in a known location on the user's system. * A vulnerability that involves performing a drag-and-drop operation during dynamic HTML (DHTML) events in Internet Explorer. This vulnerability could allow a file to be saved in a target location on the user's system if the user clicks a link. No dialog box would request that the user approve this download. To exploit one of these vulnerabilities, an attacker would have to host a malicious Web site that contains a Web page that has a specially-crafted link. The attacker would then have to persuade a user to click that link. The attacker could also create an HTML e-mail message that has a specially-crafted link, and then persuade the user to view the HTML e-mail message and then click the malicious link. If the user clicked this link, code of the attacker's choice could be saved on the user's computer in a targeted location. As with the previous Internet Explorer cumulative updates that were released with bulletins MS03-004, MS03-015, MS03-020, MS03-032, and MS03-040, this cumulative update causes the window.showHelp( ) control to no longer work if you have not applied the HTML Help update. If you have installed the updated HTML Help control from Knowledge Base article 811630, you will still be able to use HTML Help functionality after you apply this update. Mitigating factors: There are three common mitigating factors across all the vulnerabilities: * By default, Internet Explorer on Windows Server 2003 runs in Enhanced Security Configuration. This default configuration of Internet Explorer blocks automatic exploitation of this attack. If Internet Explorer Enhanced Security Configuration has been disabled, the protections that are put in place that prevent these vulnerabilities from being automatically exploited would be removed. * In the Web-based attack scenario, the attacker would have to host a Web site that contains a Web page that is used to exploit these vulnerabilities. An attacker would have no way to force a user to visit a malicious Web site. Instead, the attacker would have to lure them there, typically by getting them to click a link that takes them to the attacker's site. * By default, Outlook Express 6.0, Outlook 2002 and Outlook 2003 open HTML e-mail messages in the Restricted sites zone. Additionally, Outlook 98 and 2000 open HTML e-mail messages in the Restricted sites zone if the Outlook E-mail Security Update has been installed. The risk of attack from the HTML email vector can be significantly reduced if the following conditions are met: * You have applied the patch included with Microsoft Security bulletin MS03-040 * You are using Internet Explorer 6 or later * You are using the Microsoft Outlook Email Security Update or Microsoft Outlook Express 6.0 and higher, or Microsoft Outlook 2000 or higher in their default configuration. * If an attacker exploited these vulnerabilities, they would gain only the same privileges as the user. Users whose accounts are configured to have few privileges on the system would be at less risk than ones who operate with administrative privileges. In addition, there are two individual mitigating factors for the XML Object Vulnerability: * A Web page that tried to exploit this vulnerability would present the user with a prompt to download an HTML file. An attacker could only access files on the user's system if the user accepted this prompt. * An attacker can only access files that are in a known location on the user's system. Severity Rating: ******************************************************************************************* Internet Internet Internet Explorer Internet Internet Explorer Explorer 6 and Internet Explorer Explorer 6 SP1 5.01 SP2, 5.5 SP2 Explorer 6 SP1 6 SP1 for for Windows SP3, SP4 (All versions Windows Server 2003 earlier than Server (64-Bit) Windows Server 2003 2003) ******************************************************************************************* Cross-Domain Critical Critical Critical Moderate Moderate Vulnerabilities ******************************************************************************************* XML Object Not Moderate Moderate Low Low Vulnerability affected ******************************************************************************************* Drag-and-Drop Important Important Important Moderate Moderate Operation Vulnerability ******************************************************************************************* Aggregate Critical Critical Critical Moderate Moderate Severity of All Issues Included in This Update ******************************************************************************************* The above http://www.microsoft.com/technet/security/topics/rating.asp assessment is based on the types of systems that are affected by the vulnerability, their typical deployment patterns, and the effect that exploiting the vulnerability would have on them. Vulnerability identifier: * ExecCommand Cross Domain Vulnerability: CAN-2003-0814 * Function Pointer Override Cross Domain Vulnerability: CAN-2003-0815 * Script URLs Cross Domain Vulnerability: CAN-2003-0816 * XML Object Vulnerability: CAN-2003-0817 * Drag-and-Drop Operation Vulnerability: : CAN-2003-0823 Tested Versions: Microsoft tested Internet Explorer 5.01 Service Pack 2, Internet Explorer Service Pack 3, Internet Explorer Service Pack 4, Internet Explorer 5.5 Service Pack 2, Internet Explorer 6.0, and Internet Explorer 6.0 Service Pack 1 to assess whether they are affected by these vulnerabilities. Previous versions are no longer supported, and may or may not be affected by these vulnerabilities. Workarounds Microsoft has tested the following workarounds that apply across all the vulnerabilities. These workarounds help block known attack vectors, however they will not correct the underlying vulnerabilities. Workarounds may reduce functionality in some cases; in such cases, the reduction in functionality is identified below. Prompt before running ActiveX controls and active scripting in the Internet zone and in the Intranet zone You can help protect against these vulnerabilities by changing your settings for the Internet security zone to prompt before running ActiveX controls. To do this, follow these steps: 1. In Internet Explorer, click Internet Options on the Tools menu. 2. Click the Security tab. 3. Click Internet, and then click Custom Level. 4. Under Settings, in the ActiveX controls and plug-ins section, under Run ActiveX controls and plug-ins, click Prompt. 5. In the Scripting section, under Active Scripting, click Prompt, and then click OK. 6. Click Local intranet, and then click Custom Level. 7. Under Settings, in the ActiveX controls and plug-ins section, under Run ActiveX controls and plug-ins, click Prompt 8. In the Scripting section, under Active Scripting, click Prompt. 9. Click OK two times to return to Internet Explorer. Impact of Workaround: There are side effects to prompting before running ActiveX controls. Many Web sites that are on the Internet or on an intranet use ActiveX to provide additional functionality. For example, an online e-commerce site or banking site may use ActiveX controls to provide menus, ordering forms, or even account statements. Prompting before running ActiveX controls is a global setting that affects all Internet and Intranet sites. You will be prompted frequently when you enable this workaround. For each prompt, if you feel you trust the site that you are visiting, click Yes to run ActiveX controls. If you do not want to be prompted for all these sites, use the "Restrict Web sites to only your trusted Web sites" workaround. Restrict Web sites to only your trusted Web sites After you set Internet Explorer to require a prompt before it runs ActiveX in the Internet zone and in the Intranet zone, you can add sites that you trust to Internet Explorer's Trusted sites zone. This will allow you to continue to use trusted Web sites exactly as you do today, while helping to protect you from this attack on untrusted sites. Microsoft recommends that you only add sites that you trust to the Trusted sites zone. To do this, follow these steps: 1. In Internet Explorer, click Tools, click Internet Options, and then click the Security tab. 2. In the Select a Web content zone to specify its current security settings box, click Trusted Sites, and then click Sites. 3. If you want to add sites that do not require an encrypted channel, click to clear the Require server verification (https:) for all sites in this zone check box. 4. In the Add this Web site to the zone box, type the URL of a site that you trust, and then click Add. 5. Repeat these steps for each site that you want to add to the zone. 6. Click OK two times to accept the changes and return to Internet Explorer. Add any sites that you trust not to take malicious action on your computer. One in particular that you may want to add is "*.windowsupdate.microsoft.com" (without the quotes). This is the site that will host the update, and it requires the use of an ActiveX control to install the update. Impact of Workaround: For those sites that you have not configured to be in your Trusted sites zone, their functionality will be impaired if they require the use of ActiveX controls to function correctly. Adding sites to your Trusted sites zone will allow them to be able to download the ActiveX control that they require to function correctly. However you should only add Web sites you trust to the Trusted sites zone. Install Outlook E-mail Security Update if you are using Outlook 2000 SP1 or earlier By default, the Outlook Email Security Update causes Outlook 98 and 2000 to open HTML e-mail messages in the Restricted sites zone. By default, Outlook Express 6.0, Outlook 2002, and Outlook 2003 open HTML e-mail messages in the Restricted sites zone. Customers who use any of these products are at reduced risk from an e-mail-borne attack that tries to exploit this vulnerability, unless the user clicks a malicious link in the e-mail message. If you are using Outlook 2002 or Outlook Express 6.0 SP1 or later, read e-mail messages in plain text format to help protect yourself from the HTML e-mail attack vector Microsoft Outlook 2002 users who have applied Service Pack 1 or later and Outlook Express 6.0 users who have applied Service Pack 1 or later can enable a feature that will enable them to view all non- digitally-signed e-mail messages or non-encrypted e-mail messages in plain text only. Digitally-signed e-mail messages and encrypted e-mail messages are not affected by the setting and may be read in their original formats. Information about how to enable this setting in Outlook 2002 can be found in the following Knowledge Base article: http://support.microsoft.com/default.aspx?scid=kb;en-us;307594 Information about how to enable this setting in Outlook Express 6.0 can be found in the following Knowledge Base article: http://support.microsoft.com/?kbid=291387 Impact of Workaround: E-mail that is viewed in plain text format cannot contain pictures, specialized fonts, animations, or other rich content. Additionally: * The changes are applied to the preview pane and to open messages. * Pictures become attachments to avoid loss of message content. * Because the message is still in Rich Text Format or in HTML format in the store, the object model (custom code solutions) may behave unexpectedly because the message is still in Rich Text Format or in HTML format in the mail store. Security Update Information * Internet Explorer 6 SP1 for Windows XP, Windows XP SP1, Windows 2000 SP2, Windows 2000 SP3, Windows 2000 SP4, Windows NT 4.0 SP6a, Windows Millennium Edition, Windows 98, and Windows 98 Second Edition * Internet Explorer 6 SP1 (64-Bit) for Windows XP 64-Bit Edition * Internet Explorer 6 SP1 on Windows Server 2003 * Internet Explorer 6 SP1 (64-Bit) on Windows 2003 64-Bit Versions and on Windows XP 64-Bit Edition, Version 2003 * Internet Explorer 6 for Windows XP * Internet Explorer 5.5 SP2 for Windows 2000 SP2, Windows 2000 SP3, Windows 2000 SP4, Windows NT 4.0 SP6a, Windows Millennium Edition, Windows 98, and Windows 98 Second Edition * Internet Explorer 5.01 for Windows 2000 SP2 * Internet Explorer 5.01 for Windows 2000 SP3 * Internet Explorer 5.01 for Windows 2000 SP4 Acknowledgments Microsoft thanks the following for working with us to help protect customers: * jelmer (jkuperus@planet.nl) for reporting the XML Object (CAN-2003-0817) issue to us. Obtaining other security updates: Updates for other security issues are available from the following locations: * Security updates are available from the Microsoft Download Center and can be most easily found by doing a keyword search for "security_patch." * Updates for consumer platforms are available from the Windows Update Web site. Support: * Technical support is available from Microsoft Product Support Services at 1-866-PCSAFETY. There is no charge for support calls associated with security patches. * International customers can get support from their local Microsoft subsidiaries. There is no charge for support associated with security updates. Information on how to contact Microsoft support is available at http://support.microsoft.com/common/international.aspx Security Resources: * The Microsoft TechNet Security Web site provides additional information about security in Microsoft products. * Microsoft Software Update Services: http://www.microsoft.com/sus/ * Microsoft Baseline Security Analyzer (MBSA) details: http://www.microsoft.com/mbsa. Please see http://support.microsoft.com/default.aspx?scid=kb;EN-US;306460 for list of security updates that have detection limitations with MBSA tool. * Windows Update Catalog: http://support.microsoft.com/default.aspx?scid=kb;EN-US;323166 * Windows Update: http://windowsupdate.microsoft.com * Office Update: http://office.microsoft.com/officeupdate/ * Software Update Services (SUS): Microsoft Software Update Services (SUS) enables administrators to quickly and reliably deploy the latest critical updates and security updates to Windows® 2000 and Windows Server™ 2003-based servers, as well as to desktop computers running Windows 2000 Professional or Windows XP Professional. For information about how to deploy this security patch with Software Update Services, visit the following Microsoft Web site: http://www.microsoft.com/sus/ Systems Management Server (SMS): Systems Management Server can provide assistance deploying this security update. For information about Systems Management Server visit the SMS Web Site. SMS also provides several additional tools to assist administrators in the deployment of security updates such as the SMS 2.0 Software Update Services Feature Pack and the SMS 2.0 Administration Feature Pack. The SMS 2.0 Software Update Services Feature Pack utilizes the Microsoft Baseline Security Analyzer and the Microsoft Office Detection Tool to provide broad support for security bulletin remediation. Some software updates may require administrative rights following a restart of the computer. Note: The inventory capabilities of the SMS 2.0 Software Update Services Feature Pack may be used for targeting updates to specific computers, and the SMS 2.0 Administration Feature Pack's Elevated Rights Deployment Tool can be used for installation. This provides optimal deployment for updates that require explicit targeting using Systems Management Server and administrative rights after the computer has been restarted. 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 (November 11, 2003): Bulletin published [***** End MS03-048 *****] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of Microsoft 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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