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             __________________________________________________________

                       The U.S. Department of Energy
                    Computer Incident Advisory Capability
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                             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)

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