AUSCERT External Security Bulletin Redistribution
              ESB-98.118 -- SGI Security Advisory 19980701-01-P
         IRIX 6.4 ioconfig(1M) and disk_bandwidth(1M) Vulnerability
                                23 July 1998


Silicon Graphics Inc. has released the following advisory concerning
a vulnerability discovered in both ioconfig(1M) and disk_bandwidth(1M)
programs that can lead to a root compromise of the system.

The following security bulletin is provided as a service to AusCERT's
members.  As AusCERT did not write this document, AusCERT has had
no control over its content.  As such, the decision to use any or
all of this information is the responsibility of each user or
organisation, and should be done so in accordance with site policies
and procedures.

NOTE: This is only the original release of the security bulletin.
It will not be updated when the original bulletin is.  If downloading
at a later date, it is recommended that the bulletin is retrieved
from the original authors to ensure that the information is still

Contact information for SGI is included in the Security Bulletin
below.  If you have any questions or need further information,
please contact them directly.

Previous advisories and external security bulletins can be retrieved


If you believe that your system has been compromised, contact AusCERT or
your representative in FIRST (Forum of Incident Response and Security

Internet Email: auscert@auscert.org.au
Facsimile:	(07) 3365 7031
Telephone:	(07) 3365 4417 (International: +61 7 3365 4417)
		AusCERT personnel answer during Queensland business hours
		which are GMT+10:00 (AEST).
		On call after hours for emergencies.

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                Silicon Graphics Inc. Security Advisory

        Title:   IRIX 6.4 ioconfig(1M) and disk_bandwidth(1M) Vulnerability
        Number:  19980701-01-P
        Date:    July 20, 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 IRIX ioconfig(1M) program assigns logical controller numbers to all I/O
devices on a Silicon Graphics Origin or Onyx2 system.

The IRIX disk_bandwidth(1M) program is used to determine the number of I/O
operations that can be performed on a given disk device on an Origin or Onyx2

Both programs are normally only used by IRIX System administrators.

Unfortunately, a vulnerability has been discovered in both ioconfig(1M) and
disk_bandwidth(1M) programs that can lead to a root compromise of the system.

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 ioconfig(1M)/disk_bandwidth(1M) programs are installed by default on all
IRIX 6.4 S2MP Origin and Onyx2 systems.

A local user account on the vulnerable system is required in order to
exploit the ioconfig(1M)/disk_bandwidth(1M) vulnerability locally and remotely.

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

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

The steps below can be used to remove the vulnerability by restricting
permissions of the ioconfig(1M)/disk_bandwidth(1M) programs to the root user.

     1) Become the root user on the system.

           % /bin/su -

     2) Verify the vulnerable ioconfig(1M)/disk_bandwidth(1M) programs
        are installed. Only IRIX 6.4 S2MP for Origin/Onyx2 is vulnerable.

           # uname -R
           6.4 S2MP+OCTANE

     3) Remove permissions on the vulnerable ioconfig(1M) and
        disk_bandwidth(1M) programs.

           # /bin/chmod 500 /sbin/ioconfig
           # /bin/chmod 500 /sbin/disk_bandwidth

                           *** NOTE ***

            Removing permissions from the vulnerable programs will
            prevent non-root users from accessing ioconfig(1M) and

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

              # ls -al /sbin/ioconfig /usr/sbin/disk_bandwidth
              -r-x------    1 root sys   34024 Feb 20 16:53 ioconfig
              -r-x------    1 root sys   17604 Dec 18  1997 disk_bandwidth

     5) Return to previous user level.

                # exit

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

Silicon Graphics wishes to thank 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.

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