Original release date: October 08, 2001<BR> Last revised: Mon Oct 15 09:32:36 EDT 2001<BR> Source: CERT/CC<BR> <P>A complete revision history can be found at the end of this file. <A NAME="affected"> <H3>Systems Affected</H3> Systems running: <UL> <LI>Windows <UL> <LI>Microsoft Excel 2000 <LI>Microsoft Excel 2002 <LI>Microsoft PowerPoint 2000 <LI>Microsoft PowerPoint 2002 </UL> <br> <LI>Macintosh <UL> <LI>Microsoft Excel 98 <LI>Microsoft Excel 2001 <LI>Microsoft PowerPoint 98 <LI>Microsoft PowerPoint 2001 </UL></UL> </UL> <br> <p> According to Microsoft, versions of Excel and PowerPoint (or indeed, other products in the Office suite) prior to this may be affected, but may be outside of hotfix support. [For example, Symantec <a href="http://securityresponse.symantec.com/avcenter/security/Content/2001.10.04.html"> states</a> that Microsoft Excel 97 and Microsoft Powerpoint 97 are vulnerable.] Because Microsoft Excel 97 and Microsoft Powerpoint 97 are outside of the hotfix support window, these products may be vulnerable, but not eligible for a hotfix. For more information regarding hotfix eligibility status, please see the <a href="http://support.microsoft.com/directory/discontinue.asp">Microsoft Product Support Services</a> webpage. In general, Microsoft no longer tests software outside of hotfix status for vulnerabilities, and does not provide patches to address vulnerabilities that may be discovered in that software. <p> <b>Quoting from Microsoft Security Bulletin MS01-050</b> </p> <p> <i>It's important to understand that Excel and PowerPoint 97 do not have the same macro security framework as Excel and PowerPoint 2000 and 2002. The Excel and PowerPoint 97 macro security framework lacks many key features that the 2000 and 2002 macro security framework has, including a digital signature trust model that allows trusted, signed macros to be differentiated from untrusted, unsigned macros. Under this older framework, it is difficult for a user to make an informed decision regarding the trustworthiness of macros. In addition, as noted under "Tested Versions", Excel and PowerPoint 97 are no longer supported products. Because of these two issues, customers who are concerned about macro security are urged to upgrade to a support version with a more robust macro security model.</i> </p> </p> <A NAME="overview"> <H2>Overview</H2> <P> An intruder can include a specially crafted macro in a Microsoft Excel or PowerPoint document that can avoid detection and run automatically regardless of the security settings specified by the user. </P> <A NAME="description"> <H2>I. Description</H2> <P> Microsoft Excel and PowerPoint scan documents when they are opened and check for the existence of macros. If the document contains macros, the user running Excel or PowerPoint is alerted and asked if he would like the macros to be run. However, Microsoft Excel and PowerPoint may not detect malformed macros, so a user can unknowingly run macros containing malicious code when opening an Excel or PowerPoint document. <p>An intruder who can entice or deceive a victim into opening a document using a vulnerable version of Excel or PowerPoint could take any action the victim could take, including, but not limited to <ul> <li>reading, deleting, or modifying data, either locally or on open file shares</li> <li>modifying security settings (including macro virus protection settings)</li> <li>sending electronic mail</li> <li>posting data to or retrieving data from web sites</li> </ul> <p>For more information, please see <dl> <dd> <A href="http://securityresponse.symantec.com/avcenter/security/Content/2001.10.04.html">http://securityresponse.symantec.com/avcenter/security/Content/2001.10.04.html</a> <dd> <a href="http://www.microsoft.com/technet/treeview/default.asp?url=/technet/security/bulletin/MS01-050.asp">http://www.microsoft.com/technet/treeview/default.asp?url=/technet/security/bulletin/MS01-050.asp</a> </p> </dd> </dl> <P>Given the strong potential for widespread abuse of this vulnerability, we strongly recommend that you apply patches as soon as you are able. For example, the Melissa virus which spread in March of 1999 used social engineering to convince victims to execute a macro embedded in a Microsoft Word document. For more information, see the CERT/CC Advisory listed below. <dl> <dd> <a href="http://www.cert.org/advisories/CA-1999-04.html">http://www.cert.org/advisories/CA-1999-04.html</a> </p> </dd> </dl> <p>As a general practice, everyone should be aware of the potential damage that Trojan horses and other kinds of malicious code can cause to <i>any</i> platform. For more information, see <dl> <dd><A HREF="http://www.cert.org/advisories/CA-1999-02.html">http://www.cert.org/advisories/CA-1999-02.html</a> </dd> </dl> <P>This vulnerability has been assigned the identifier CAN-2001-0718 by the Common Vulnerabilities and Exposures (<a href="http://cve.mitre.org/">CVE</a>) group: <dl> <dd><A HREF="http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2001-0718">http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2001-0718</a> </dd> </dl> </p> <A NAME="impact"> <H2>II. Impact</H2> <p> An attacker can execute arbitrary code on the target system with the privileges of the victim running Excel or PowerPoint.</p> <A NAME="solution"> <H2>III. Solution</H2> <p> <H4>Apply a patch</H4> <A HREF="#vendors">Appendix A</a> contains information from vendors who have provided information for this advisory. We will update the appendix as we receive more information. If a vendor's name does not appear, then the CERT/CC did not hear from that vendor. Please contact your vendor directly. <p>Until a patch can be applied, and as a general practice, we recommend using caution when opening attachments. However, it is important to note that relying on the "From" line in an electronic mail message is not sufficient to authenticate the origin of the document. <A NAME="vendors"> <H2>Appendix A. - Vendor Information</H2> <P>This appendix contains information provided by vendors for this advisory. When vendors report new information to the CERT/CC, we update this section and note the changes in our revision history. If a particular vendor is not listed below, we have not received their comments.</P> <p> <A NAME="microsoft"> <H4>Microsoft Corporation</H4> <p>See <a href="http://www.microsoft.com/technet/treeview/default.asp?url=/technet/security/bulletin/MS01-050.asp">Microsoft Security Bulletin MS01-050</a></p> <!-- end vendor --> </p> <A NAME="references"><H2>Appendix B. - References</H2></A> <ol> <li><A href="http://securityresponse.symantec.com/avcenter/security/Content/2001.10.04.html">http://securityresponse.symantec.com/avcenter/security/Content/2001.10.04.html</a> <li><a href="http://www.microsoft.com/technet/treeview/default.asp?url=/technet/security/bulletin/MS01-050.asp">http://www.microsoft.com/technet/treeview/default.asp?url=/technet/security/bulletin/MS01-050.asp</a><br> <li><a href="http://www.kb.cert.org/vuls/id/287067">http://www.kb.cert.org/vuls/id/287067</a><BR> <li><a href="http://www.cert.org/advisories/CA-1999-04.html">http://www.cert.org/advisories/CA-1999-04.html</a><br> <li><A HREF="http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2001-0718">http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2001-0718</a> </ol> <HR> <HR NOSHADE> <P>The CERT Coordination Center thanks Peter Ferrie and <a href="http://securityresponse.symantec.com">Symantec Security Response</a>, who discovered this vulnerability and published the information in their <A href="http://securityresponse.symantec.com/avcenter/security/Content/2001.10.04.html"> advisory.</a> Additionally, we thank <a href="http://www.microsoft.com">Microsoft Corporation</a>, who published an <a href="http://www.microsoft.com/technet/treeview/default.asp?url=/technet/security/bulletin/MS01-050.asp">advisory</a> on this issue.</P> <P></P> <HR NOSHADE> <P>Author: <A HREF="mailto:cert@cert.org?subject=CA-2001-28%20Feedback%20VU%23287067">Ian A. Finlay and Shawn V. Hernan.</A> <P></P> <!--#include virtual="/include/footer_nocopyright.html" --> <P>Copyright 2001 Carnegie Mellon University.</P> <P>Revision History <PRE> October 8, 2001: initial release October 11,2001: added information to systems affected section October 15,2001: revised systems affected section </PRE> |