-----BEGIN PGP SIGNED MESSAGE----- __________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN PGP Additional Decryption Keys (ADKs) Vulnerability August 28, 2000 15:00 GMT Number K-070 ______________________________________________________________________________ PROBLEM: An implementation flaw allows unsigned Additional Decryption Keys (ADKs) to be added to a certificate and used for encryption. PLATFORM: Those running PGP versions 5.5.x through 6.5.3, both domestic and international. DAMAGE: The attacker who inserted the unsigned ADK can decrypt messages that were later encrypted using the altered certificate. SOLUTION: It is up to the sender to verify that the certificate that is used for encryption does not contain any unsigned ADKs. Network Associates, Inc. has released many product updates and HotFixes for this problem. Apply the appropriate update and/or HotFix. ______________________________________________________________________________ VULNERABILITY The risk is MEDIUM. The vulnerability is difficult to exploit. ASSESSMENT: ______________________________________________________________________________ [ Start Network Associates, Inc. Advisory ] PGP ADK Security Advisory On the morning of Thursday, August 24, researchers in Germany announced the discovery of a bug in PGP versions 5.5 through 6.5.3, regarding how those versions handle unauthorized Additional Decryption Key (ADK) additions to the unhashed/unsigned areas of PGP keys. This page provides the most up-to-date information regarding this issue and what steps Network Associates is taking. Please refer back to this page in the future for updates. As reported in the CERT advisory, exploitation of this bug is unlikely due to the unique circumstances under which an attack could be launched. To date, there have been no reported exploits. WHAT'S NEW Network Associates performed a thorough inspection of the world's largest public PGP keyserver (certserver.pgp.com), containing nearly 1.2 million PGP keys, and found that no keys contained on the server were affected by this issue. A software update has been applied to certserver.pgp.com and pgpkeys.mit.edu which automatically cleanses keys as they are uploaded to the servers. The cleansing process removes any signatures that have been tampered with (containing offending unhashed subpackets). A HotFix for PGP Certificate Server customers will be released soon that contains this update. Network Associates strongly recommends that customers download and install this HotFix on their PGP Certificate Servers as soon as it is available. We have released a new command line utility, PGPrepair 1.0, that will scan PGP keyrings and look for (and can repair) keys that have been tampered with. This utility is available on Windows, Solaris and Linux platforms. The PGPrepair tool is designed to repair keyrings created and/or used by PGP versions 2.6.2 and above. It can be applied to personal keyrings or to large keyserver keyrings (including PGP Certificate Servers). We have also released many product updates and HotFixes which resolve this issue. For more information about which versions of PGP are affected by this issue, what product updates/HotFixes are available and what we recommend you do regarding this issue, please visit the PGP Product Information Center for the ADK Security-Related Bug. Network Associates/PGP Security plans to release a detailed, formal advisory about this issue in the near future. (C) 2000, Network Associates, Inc. and its affiliated Companies. All Rights Reserved. [ End Network Associates, Inc. Advisory ] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of Network Associates, Inc. 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 FAX: +1 925-423-8002 STU-III: +1 925-423-2604 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), use one of the following methods to contact CIAC: 1. Call the CIAC voice number 925-422-8193 and leave a message, or 2. Call 888-449-8369 to send a Sky Page to the CIAC duty person or 3. Send e-mail to 4498369@skytel.com, or 4. Call 800-201-9288 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://www.ciac.org/ (or http://ciac.llnl.gov -- they're the same machine) Anonymous FTP: ftp.ciac.org (or ciac.llnl.gov -- they're the same machine) Modem access: +1 (925) 423-4753 (28.8K baud) +1 (925) 423-3331 (28.8K baud) 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. LAST 10 CIAC BULLETINS ISSUED (Previous bulletins available from CIAC) K-060: Microsoft's Malformed E-Mail Header Vulnerability K-061: Microsoft "Office HTML" & "IE" Script Vulnerabilities K-062: Vulnerabilities in Lotus Notes Domino Aired at DefCon 8 K-063: Netscape - Java Vulnerability K-064: Linux Kernel Capability Vulnerability K-065: Microsoft "Specialized Header" Vulnerability K-066: IRIX telnetd vulnerability K-067: FreeBSD - dhclient vulnerable to malicious dhcp server K-068: Automated Web Interface Scans IIS for Multiple Vulnerabilities K-069: Input Validation Problem in rpc.statd -----BEGIN PGP SIGNATURE----- Version: 4.0 Business Edition iQCVAwUBOaqSKLnzJzdsy3QZAQFZRQQAzv/Ux6VPayvo9AMt8qX8lCBSt5nnngtW dtXbvvjrT+oeFf3p8BFW3OcsY3Vp8+ljW2GeamYlFNt+0EL156ryYQNx7Upy13Yo 8U+B1XHMDZJidGZSdXLvnFToMIW6CE67BKtkBLIxzhW6HY2cZkaZCbwOoKhqHJu4 7HVe+Wnawtk= =iPPS -----END PGP SIGNATURE-----