-----BEGIN PGP SIGNED MESSAGE----- [ For Public Release ] __________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Netscape Navigator Security Vulnerability June 26, 1997 17:00 GMT Number H-76 ______________________________________________________________________________ PROBLEM: A problem has been identified in the Netscape Navigator. PLATFORM: All platforms running Netscape Navigator 2.0, 3.0, and Communicator 4.0. DAMAGE: This vulnerability may allow a Web site operator to retrieve known files from the hard disks of visiting users by mimicking the submission of a form. SOLUTION: Apply the workaround or the appropriate patch provided below. ______________________________________________________________________________ VULNERABILITY The exploit is not currently available but knownledge of this ASSESSMENT: vulnerability has been highly publicized by the media. ______________________________________________________________________________ Introduction ============ Recently, the Internet community was made aware of a bug in the Netscape Navigator. Netscape engineers were able to recreated the bug in Netscape Communicator and Navigator 2.0 and 3.0. Known as the privacy bug, it may allow a Web site operator to retrieve known files from the hard disks of visiting users by mimicking the submission of a form. Under ordinary circumstances, users browsing on known, trusted sites are not at risk. However, if a user visits an unknown, untrusted site, the operator of that site could potentially retrieve files from a user's hard disk through an obscure series of steps. To access a file on the hard drive the Web site operator would need to know the exact name and location of the file. Even though the bug has been highly publicized, this factor in itself limits the possibility of this vulnerability being exploited. Netscape released the following statement: "The execution of this attack requires specific knowledge of the user's machine to cause harm and so is unlikely to be reproduced. Because this specific bug has existed for more than a year and a half since Navigator 2.0 -- and Netscape has never had a report about this bug or any loss based on this bug -- we believe the risk to users from this bug is relatively low." CIAC recommends that you apply the workarounds or the appropriate patch provided below. Workarounds =========== To remove any risk of this bug, Navigator users should download the updated version of Communicator or Navigator, that includes the fix. In the interim, users of Navigator 3.0 and Communicator 4.0 can take the following steps to enable warning dialog boxes to detect and cancel form submissions: In Navigator 3.0: Go to the Options menu and select Security Preferences. Select the "Submitting a Form Insecurely" preference to enable that warning dialog box. In Navigator 4.0: Select the lock in the toolbar to open the Security Advisor. Select Navigator, then select the "Sending Unencrypted Information to a Site" preference to enable that warning dialog box. Patches or Upgrades =================== Communicator 4.01 for Windows (includes the fix for privacy bug) http://home.netscape.com/download/client_download.html?communicator4.01 Navigator 3.0 Fix pending per Netscape ______________________________________________________________________________ CIAC wishes to acknowledge the contributions of Netscape 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: +1 510-422-8193 FAX: +1 510-423-8002 STU-III: +1 510-423-2604 E-mail: ciac@llnl.gov For emergencies and off-hour assistance, DOE, DOE contractor sites, and the NIH may contact CIAC 24-hours a day. During off hours (5PM - 8AM PST), call the CIAC voice number 510-422-8193 and leave a message, or call 800-759-7243 (800-SKY-PAGE) to send a Sky Page. CIAC has two Sky Page PIN numbers, the primary PIN number, 8550070, is for the CIAC duty person, and the secondary PIN number, 8550074 is for the CIAC Project Leader. Previous CIAC notices, anti-virus software, and other information are available from the CIAC Computer Security Archive. World Wide Web: http://ciac.llnl.gov/ Anonymous FTP: ciac.llnl.gov (198.128.39.53) Modem access: +1 (510) 423-4753 (28.8K baud) +1 (510) 423-3331 (28.8K baud) CIAC has several self-subscribing mailing lists for electronic publications: 1. 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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. LAST 10 CIAC BULLETINS ISSUED (Previous bulletins available from CIAC) H-66: Vulnerability in suidperl (sperl) H-67: Red Hat Linux X11 Libraries Buffer Overflow H-68: Windows95 Network Password Vulnerability H-69: Vulnerability in getopt (3) H-70: Vulnerability in rpcbind H-71: Vulnerability in the at(1) program H-72: SunOS eeprom Vulnerability H-73: SunOS chkey Vulnerability H-74: Unix lpr Buffer Overrun Vulnerability H-75: Solaris Solstice AdminSuite Vulnerabilities -----BEGIN PGP SIGNATURE----- Version: 4.0 Business Edition iQCVAwUBM7LNxrnzJzdsy3QZAQGxIgQAt9hzDjGS5aFRvSssHVlv8ghioQbJOWWV K+bJuBiSwzGLBuGJnpB24KRVvl6sh0uMRIlOf8fiD6b5Tk+GBeNK/vDXs5keOXhX xwbEMHKWjiH1gWomsK0aGkBDhKfyFyzBaBDPzHP4pJJqNMBOVbjFH9GI98KKSqI6 x8VOzZm3Hs0= =hfEB -----END PGP SIGNATURE-----