FedCIRC Advisory FA-99-15 Buffer Overflow in amd
                                       
   Original release date: September 16, 1999
   Last revised: --
   Source: CERT/CC
   
   A complete revision history is at the end of this file.
   
  Systems Affected
  
     * Systems running amd, the Berkeley Automounter Daemon
       
I. Description

   There is a buffer overflow vulnerability in the logging facility of
   the amd daemon.
   
   This daemon automatically mounts file systems in response to attempts
   to access files that reside on those file systems. Similar
   functionality on some systems is provided by a daemon named
   automountd.
   
   Systems that include automounter daemons based on BSD 4.x source code
   may also be vulnerable. A vulnerable implementation of amd is included
   in the am-utils package, provided with many Linux distributions.
   
II. Impact

   Remote intruders can execute arbitrary code as the user running the
   amd daemon (usually root).
   
III. Solution

    Install a patch from your vendor
    
   Appendix A contains information provided by vendors for this advisory.
   We will update the appendix as we receive more information. If you do
   not see your vendor's name, the CERT/CC did not hear from that vendor.
   Please contact your vendor directly.
   
   We will update this advisory as more information becomes available.
   Please check the CERT/CC Web site for the most current revision.
   
    Disable amd
    
   If you are unable to apply a patch for this problem, you can disable
   the amd daemon to prevent this vulnerability from being exploited.
   Disabling amd may prevent your system from operating normally.
   
Appendix A. Vendor Information

    BSDI
    
   BSD/OS 4.0.1 and 3.1 are both vulnerable to this problem if amd has
   been configured. The amd daemon is not started if it has not been
   configured locally. Mods (M410-017 for 4.0.1 and M310-057) are
   available via ftp from [1]ftp://ftp.bsdi.com/bsdi/patches or via our
   web site at [2]http://www.bsdi.com/support/patches
   
    Compaq Computer Corporation
    
   Not vulnerable
   
    Data General
    
   DG/UX is not vulnerable to this problem.
   
    Erez Zadok (am-utils maintainer)
    
   The latest stable version of am-utils includes several important
   security fixes. To retrieve it, use anonymous ftp for the following
   URL
   
   [3]ftp://shekel.mcl.cs.columbia.edu/pub/am-utils/
          
   The MD5 checksum of the am-utils-6.0.1.tar.gz archive is
   
   MD5 (am-utils-6.0.1.tar.gz) = ac33a4394d30efb4ca47880cc5703999
          
   The simplest instructions to build, install, and run am-utils are as
   follows:
    1. Retrieve the package via FTP.
    2. Unpack it:
       $ gunzip am-utils-6.0.1.tar.gz
       $ tar xf am-utils-6.0.1.tar
       If you have GNU tar and gunzip, you can issue a single command:
       $ tar xzf am-utils-6.0.1.tar.gz
    3. Build it:
       $ cd am-utils-6.0.1
       $ ./buildall
       This would configure and build am-utils for installation in
       /usr/local. If you built am-utils in the past using a different
       procedure, you may repeat that procedure instead. For example, to
       build am-utils using shared libraries and to enable debugging, use
       either:
       $ ./buildall -Ds -b
       or
       $ ./configure --enable-debug=yes --enable-shared --disable-static
       You may run "./configure --help" to get a full list of available
       options. You may run "./buildall -H" to get a full list of options
       it offers. The buildall script is a simple wrapper script that
       configures and builds am-utils for the most common desired
       configurations.
    4. Install it:
       $ make install
       This would install the programs, scripts, libraries, manual pages,
       and info pages in /usr/local/{sbin,bin,lib,man,info}, etc.
    5. Run it.
       Assuming you have an Amd configuration file in /etc/amd.conf, you
       can simply run:
       $ /usr/local/sbin/ctl-amd restart
       That will stop the older running Amd, and start a new one. If you
       use a different Amd start-up script, you may use it instead.
       
    FreeBSD
    
   Please see the FreeBSD advisory at
   
   [4]ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-99:06.
          amd.asc
          
   for information on patches for this problem.
   
    Fujitsu
    
   This vulnerability is still under investigation by Fujitsu.
   
    Hewlett-Packard Company
    
   HP is not vulnerable.
   
    IBM Corporation
    
   AIX is not vulnerable. It does not ship the am-utils package.
   
    OpenBSD
    
   OpenBSD is not vulnerable.
   
    RedHat Inc.
    
   RedHat has released a security advisory on this topic. It is available
   from our ftp server at:
   
   [5]http://www.redhat.com/corp/support/errata/RHSA1999032_O1.html
          
    SCO Unix
    
   No SCO products are vulnerable.
   
    SGI
    
   SGI does not distribute am-utils in either IRIX or UNICOS operating
   systems.
   
    Sun Microsystems, Inc.
    
   SunOS - All versions are not vulnerable.
   
   Solaris - All versions are not vulnerable.
     _________________________________________________________________
   
   The CERT Coordination Center would like to thank Erez Zadok, the
   maintainer of the am-utils package, for his assistance in preparing
   this advisory.
   ______________________________________________________________________
   
   This document is available from:
   [6]http://www2.fedcirc.gov/advisories/FA-99-15.html
   ______________________________________________________________________
   
FedCIRC Contact Information

   Email: [7]fedcirc@fedcirc.gov
          Phone: +1 888-282-0870 (24-hour toll-free hotline)
          Phone: +1 412-268-6321 (24-hour hotline)
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          Postal address:
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          Software Engineering Institute
          Carnegie Mellon University
          Pittsburgh PA 15213-3890
          U.S.A.
          
   FedCIRC personnel answer the hotline 08:00-20:00 EST(GMT-5) /
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   Copyright 1999 Carnegie Mellon University.
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   ______________________________________________________________________
   
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   Revision History
Sep 16, 1999:  Initial release

References

   1. ftp://ftp.bsdi.com/bsdi/patches
   2. http://www.bsdi.com/support/patches
   3. ftp://shekel.mcl.cs.columbia.edu/pub/am-utils/
   4. ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-99:06.amd.asc
   5. http://www.redhat.com/corp/support/errata/RHSA1999032_O1.html
   6. http://www2.fedcirc.gov/advisories/FA-99-15.html
   7. mailto:fedcirc@fedcirc.gov
   8. http://www2.fedcirc.gov/keys.html
   9. http://www.fedcirc.gov/
  10. http://www.cert.org/legal_stuff.html