-----BEGIN PGP SIGNED MESSAGE----- =============================================================================== Security Advisory CERT-NL =============================================================================== Author/Source : Olav ten Bosch Index : S-96-50 Distribution : World Page : 1 Classification: External Version: 1 Subject : Vulnerability in Microsoft Explorer Date : 30-Aug-96 =============================================================================== By courtesy of the Automated Systems Security Incident Support Team (ASSIST) we received information on a vulnerability in Microsoft Explorer version 3.0 running under Windows 95 CERT-NL recommends installing the provided security patch. ============================================================================== Automated Systems Security Incident Support Team _____ ___ ___ _____ ___ _____ | / /\ / \ / \ | / \ | | / Integritas / \ \___ \___ | \___ | | < et /____\ \ \ | \ | | \ Celeritas / \ \___/ \___/ __|__ \___/ | |_____\ Bulletin 96-16 Release date: 29 August, 1996, 8:45 AM EDT (GMT -4) SUBJECT: Microsoft Explorer version 3.0 - Security hole running under Windows 95 SUMMARY: ASSIST received information about a security vulnerability in Microsoft Explorer running under Windows 95. The vulnerability was discovered by Dirk Balfanz and Edward Felten at Princeton University. A brief description is available at "http://www.cs.princeton.edu/sip/news/Aug96-2.html". BACKGROUND: A potential attacker can exploit Microsoft's Explorer browser by employing a technique for delivering a document to the victim's browser. The document is a Microsoft Word template containing a macro programmed to execute DOS commands. The DOS commands within the macro bypass security checks. Explorer is designed to display a dialog box warning the user if a file contains a virus or malicious code. Explorer provides the user with an option to abort or proceed with the download. The exploit in Explorer bypasses the dialog box providing an opportunity to run malicious code against the user's PC. IMPACT: A potential attacker has the ability to read, modify, or delete a victim's files; insert malicious code, or open access into the victim's system. RECOMMENDED SOLUTIONS: ASSIST recommends downloading and installing a security patch provided by Microsoft. Microsoft's patch for the Explorer 3.0 is at "http://www.microsoft.com/msdownload/iepatch.htm". ============================================================================== CERT-NL is the Computer Emergency Response Team for SURFnet customers. SURFnet is the Dutch network for educational, research and related institutes. CERT-NL is a member of the Forum of Incident Response and Security Teams (FIRST). All CERT-NL material is available under: http://www.surfnet.nl/surfnet/security/cert-nl.html ftp://ftp.surfnet.nl/surfnet/net-security In case of computer or network security problems please contact your local CERT/security-team or CERT-NL (if your institute is NOT a SURFnet customer please address the appropriate (local) CERT/security-team). CERT-NL is one/two hour(s) ahead of UTC (GMT) in winter/summer, i.e. UTC+0100 in winter and UTC+0200 in summer (DST). Email: cert-nl@surfnet.nl Phone: +31 302 305 305 Fax: +31 302 305 329 Snailmail: SURFnet bv Attn. CERT-NL P.O. Box 19035 NL - 3501 DA UTRECHT The Netherlands A 7 * 24 hours phone number is available to SURFnet SSC's and FIRST members on request. ============================================================================== -----BEGIN PGP SIGNATURE----- Version: 2.6.2i iQCVAwUBMiabE2L2fnkJN/jpAQHB7wP+NwPO5s5zKn2p/i4O4rAW9J7Pap3y7COd ZbprRtWWtrw+K6hcFyv74a49HTHrXZ9wJcmyuNd+sGNyfa9TT3fa5DDRuP6rJ7R9 3olnloiiOxVZKdFvukL+YNLWFEXlNhKmH5PnElpn96IqZ8wV3MYL2UOanIaIOnLm bhxdkba/Sz8= =uAY0 -----END PGP SIGNATURE-----