AUSCERT External Security Bulletin Redistribution
           ESB-98.159 -- SGI Security Advisory 19981002-01-PX
                IRIX xterm(1) exploitable buffer overflow
                             16 October 1998


Silicon Graphics Inc. has released the following advisory concerning a
buffer overflow vulnerability in the xterm(1) program installed by default
on IRIX. This vulnerability may allow local users to gain root access.

- ---------------------------BEGIN INCLUDED TEXT--------------------


                Silicon Graphics Inc. Security Advisory

        Title:   xterm(1) exploitable buffer overflow
        Title:   CERT VB-98.04
        Number:  19981002-01-PX
        Date:    October 15, 1998

Silicon Graphics provides this information freely to the SGI user community
for its consideration, interpretation, implementation and use.   Silicon
Graphics recommends that this information be acted upon as soon as possible.

Silicon Graphics provides the information in this Security Advisory on
an "AS-IS" basis only, and disclaims all warranties with respect thereto,
express, implied or otherwise, including, without limitation, any warranty
of merchantability or fitness for a particular purpose.  In no event shall
Silicon Graphics be liable for any loss of profits, loss of business, loss
of data or for any indirect, special, exemplary, incidental or consequential
damages of any kind arising from your use of, failure to use or improper
use of any of the instructions or information in this Security Advisory.

- - -----------------------
- - --- Issue Specifics ---
- - -----------------------

The Open Group (http://www.opengroup.org/) has reported via CERT that
an exploitable buffer overflow has been discovered in xterm(1) which can lead
to a root compromise.

Silicon Graphics Inc. has investigated the issue and recommends the
following steps for neutralizing the exposure.  It is HIGHLY RECOMMENDED
that these measures be implemented on ALL vulnerable SGI systems.
This issue will be corrected in future releases of IRIX.

- - --------------
- - --- Impact ---
- - --------------

The xterm(1) program is installed by default on IRIX.

A local user account on the vulnerable system is required in order to exploit
xterm(1) program.

The exploitable buffer overflow vulnerability can lead to a root compromise.

This xterm buffer overflow vulnerability was reported by CERT VB-98.04:

This xterm vulnerability has been publicly discussed in Usenet newsgroups
and mailing lists.

- - --------------------------
- - --- Temporary Solution ---
- - --------------------------

Although patches are available for this issue, it is realized that
there may be situations where installing the patches immediately may
not be possible.

The steps below can be used to remove the vulnerability by removing
the setuid permissions of the xterm(1) program.

  1) Become the root user on the system.

                % /bin/su -

     2) Remove the setuid-root bit from the xterm binary.

                # chmod 0755 /usr/bin/X11/xterm

     3) Verify the new permissions on the program.
        Note that the program size may be different depending on release.

                # ls -al /usr/bin/X11/xterm
                -rwxr-xr-x  1 root sys  204728 May 22 16:36 /usr/bin/X11/xterm

     4) Return to previous level.

                # exit

- - ----------------
- - --- Solution ---
- - ----------------

   OS Version     Vulnerable?     Patch #      Other Actions
   ----------     -----------     -------      -------------

   IRIX 3.x          yes                       Note 1 & 2
   IRIX 4.x          yes                       Note 1 & 2
   IRIX 5.0.x        yes                       Note 1 & 2
   IRIX 5.1.x        yes                       Note 1 & 2
   IRIX 5.2          yes                       Note 1 & 2
   IRIX 5.3          yes            3142
   IRIX 6.0.x        yes                       Note 1 & 2
   IRIX 6.1          yes                       Note 1 & 2
   IRIX 6.2          yes            3143
   IRIX 6.3          yes            3144
   IRIX 6.4          yes            3351
   IRIX 6.5          yes            6.5.1      Note 3
   IRIX 6.5.1        no


     1) Upgrade to currently supported IRIX operating system.
     2) See "Temporary Solution" section.
     3) If you have not received an IRIX 6.5.1m CD for IRIX 6.5, contact your
        SGI Support Provider or download the IRIX 6.5.1 Maintenance Release
        Stream from http://support.sgi.com/

Patches are available via anonymous FTP and your service/support provider.

The primary SGI anonymous FTP site for security information and patches
is sgigate.sgi.com ( Security information and patches can be
found in the ~ftp/security and ~ftp/patches directories, respectively.

For security and patch management reasons, ftp.sgi.com (mirror of sgigate) lags
behind and does not do a real-time update of ~ftp/security and ~ftp/patches

                 ##### Patch File Checksums ####

The actual patch will be a tar file containing the following files:

Filename:                 README.patch.3142
Algorithm #1 (sum -r):    49324 8 README.patch.3142
Algorithm #2 (sum):       61084 8 README.patch.3142
MD5 checksum:             2B1A5715ACEB0CDC4C18678A8002B6F1

Filename:                 patchSG0003142
Algorithm #1 (sum -r):    29610 1 patchSG0003142
Algorithm #2 (sum):       34053 1 patchSG0003142
MD5 checksum:             6BD0AA3B67430C2068FE9144D86C74D5

Filename:                 patchSG0003142.idb
Algorithm #1 (sum -r):    32785 1 patchSG0003142.idb
Algorithm #2 (sum):       35269 1 patchSG0003142.idb
MD5 checksum:             BF1E7D0BB1E46B1BDFF9979189F5360B

Filename:                 patchSG0003142.x_eoe_sw
Algorithm #1 (sum -r):    33648 213 patchSG0003142.x_eoe_sw
Algorithm #2 (sum):       34214 213 patchSG0003142.x_eoe_sw
MD5 checksum:             B02985C04953B11AE03E11DE362A36E3

Filename:                 README.patch.3143
Algorithm #1 (sum -r):    25019 8 README.patch.3143
Algorithm #2 (sum):       21033 8 README.patch.3143
MD5 checksum:             B564135EFDC38135580A8F6B7F42CFD0

Filename:                 patchSG0003143
Algorithm #1 (sum -r):    32423 1 patchSG0003143
Algorithm #2 (sum):       27066 1 patchSG0003143
MD5 checksum:             415ACF1ACFD6EA16B264492BAA55E207

Filename:                 patchSG0003143.idb
Algorithm #1 (sum -r):    23124 1 patchSG0003143.idb
Algorithm #2 (sum):       35279 1 patchSG0003143.idb
MD5 checksum:             78CE6DFAD29790B3082AEB257A48A71A

Filename:                 patchSG0003143.x_eoe_sw
Algorithm #1 (sum -r):    40988 213 patchSG0003143.x_eoe_sw
Algorithm #2 (sum):       61141 213 patchSG0003143.x_eoe_sw
MD5 checksum:             E1CC35856C0FB1D65D8399881C5E64F4

Filename:                 README.patch.3144
Algorithm #1 (sum -r):    14474 7 README.patch.3144
Algorithm #2 (sum):       20083 7 README.patch.3144
MD5 checksum:             34700B91B362B53ADB4741D1436DA239

Filename:                 patchSG0003144
Algorithm #1 (sum -r):    28337 1 patchSG0003144
Algorithm #2 (sum):       26275 1 patchSG0003144
MD5 checksum:             BD9C4D0B2AEBE8DC674FCDF777124B38

Filename:                 patchSG0003144.idb
Algorithm #1 (sum -r):    04654 1 patchSG0003144.idb
Algorithm #2 (sum):       35038 1 patchSG0003144.idb
MD5 checksum:             F53D7B84B841E089C824603FBDFCCA32

Filename:                 patchSG0003144.x_eoe_sw
Algorithm #1 (sum -r):    62709 211 patchSG0003144.x_eoe_sw
Algorithm #2 (sum):       8545 211 patchSG0003144.x_eoe_sw
MD5 checksum:             F8275F4C685744FC32E0B46F62DE4CD4

Filename:                 README.patch.3351
Algorithm #1 (sum -r):    62541 7 README.patch.3351
Algorithm #2 (sum):       18263 7 README.patch.3351
MD5 checksum:             9B4F30943168D03E87F9A3CCE2D1E420

Filename:                 patchSG0003351
Algorithm #1 (sum -r):    51459 1 patchSG0003351
Algorithm #2 (sum):       32809 1 patchSG0003351
MD5 checksum:             128031560CEE2BA9D8988EAE99292E6C

Filename:                 patchSG0003351.idb
Algorithm #1 (sum -r):    36105 1 patchSG0003351.idb
Algorithm #2 (sum):       35002 1 patchSG0003351.idb
MD5 checksum:             24564AD152E4B65388DAA7BD9A5D205A

Filename:                 patchSG0003351.x_eoe_sw
Algorithm #1 (sum -r):    42288 212 patchSG0003351.x_eoe_sw
Algorithm #2 (sum):       26656 212 patchSG0003351.x_eoe_sw
MD5 checksum:             7A9742D4417ADBA74E64EE31DD7F2CE7

- - ------------------------
- - --- Acknowledgments ---
- - ------------------------

Silicon Graphics wishes to thank the CERT Coordination Center and the users
of the Internet Community at large for their assistance in this matter.

- - -----------------------------------------------------------
- - --- Silicon Graphics Inc. Security Information/Contacts ---
- - -----------------------------------------------------------

If there are questions about this document, email can be sent to


Silicon Graphics provides security information and patches for
use by the entire SGI community.  This information is freely
available to any person needing the information and is available
via anonymous FTP and the Web.

The primary SGI anonymous FTP site for security information and patches
is sgigate.sgi.com (  Security information and patches
are located under the directories ~ftp/security and ~ftp/patches,
respectively. The Silicon Graphics Security Headquarters Web page is
accessible at the URL http://www.sgi.com/Support/security/security.html.

For issues with the patches on the FTP sites, email can be sent to

For assistance obtaining or working with security patches, please
contact your SGI support provider.


Silicon Graphics provides a free security mailing list service
called wiretap and encourages interested parties to self-subscribe
to receive (via email) all SGI Security Advisories when they are
released. Subscribing to the mailing list can be done via the Web
(http://www.sgi.com/Support/security/wiretap.html) or by sending email
to SGI as outlined below.

% mail wiretap-request@sgi.com
subscribe wiretap <YourEmailAddress>

In the example above, <YourEmailAddress> is the email address that you
wish the mailing list information sent to.  The word end must be on a
separate line to indicate the end of the body of the message. The
control-d (^d) is used to indicate to the mail program that you are
finished composing the mail message.


Silicon Graphics provides a comprehensive customer World Wide Web site.
This site is located at http://www.sgi.com/Support/security/security.html.


For reporting *NEW* SGI security issues, email can be sent to
security-alert@sgi.com or contact your SGI support provider.  A
support contract is not required for submitting a security report.

  This information is provided freely to all interested parties and may
  be redistributed provided that it is not altered in any way, Silicon
  Graphics is appropriately credited and the document retains and
  includes its valid PGP signature.

Version: 2.6.2


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