AUSCERT External Security Bulletin Redistribution
             ESB-98.119 -- SGI Security Advisory 19980403-02-PX
                    IRIX 6.3 & 6.4 mailcap vulnerability
                                23 July 1998


Silicon Graphics Inc. has released the following advisory concerning
a vulnerability in runtask(1M) and runexec(1M) descriptor files
which can lead to a root compromise.

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 6.3 & 6.4 mailcap vulnerability
        Number:  19980403-02-PX
        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.

- - ---------------
- - ---- Update ---
- - ---------------

As part of on going security efforts, Silicon Graphics has replaced
patch 2336 with patch 3068.  Patch 2336 had an incorrect patch range.
The original text from SGI Security Advisory 19980403-01-PX has been updated
to reflect this change.

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

The System Manager sysmgr(1M) provides a web-browser-like GUI interface to
tasks that help you administer an SGI workstation. sysmgr(1M) uses multiple
tools to manage its GUI interface, two of them being runtask(1M) and

By mimicking the descriptor files of runtask(1M) or runexec(1M), an SGI user
browsing web pages or reading email can inadvertently download a
"trojan horse" runtask(1M) or runexec(1M) descriptor file. The "trojan horse"
descriptor file will execute a local System Manager Task with the privileges
of the user web browsing and can lead to a local 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 ---
- - --------------

All IRIX 6.3/6.4 users that have Mailcap entries for x-sgi-task
and x-sgi-exec have this vulnerability. On IRIX 6.3/6.4, these vulnerable
Mailcap entries are installed by default in /usr/local/lib/netscape/mailcap .
Users can add their own Mailcap entries in their home directories
($HOME/.mailcap) and these need to be inspected for the vulnerable x-sgi-task
and x-sgi-exec entries.

By default, this vulnerability requires an IRIX 6.3/6.4 user to use
Netscape Navigator to web browse or read email from a malicious site
and download a "trojan horse" System Manager Task which will execute
locally with the privileges of the user web browsing. If the user is a
privileged or root user, the "trojan horse" System Manger Task will execute
with root privileges and can lead to a root compromise.

- - --------------------------
- - --- 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.

     1) Become the root user on the system.

                % /bin/su -

     2) Edit the default Mailcap file.

                # vi /usr/local/lib/netscape/mailcap

     3) Remove the following vulnerable mailcap entries:

                application/x-sgi-task; /usr/sysadm/bin/runtask %s; 
                    description="System Administration Task"

                application/x-sgi-exec; /usr/sysadm/bin/runexec %s; 
                    description="System Administration Executable"

     4) Find any additional mailcap files and remove any vulnerable entries.

        You will need to run the find(1) command on each system you
        maintain because the command examines files on local disks only.

        Note that this is one long command, though we have separated it
        onto three lines using backslashes.

                 # find / -local -type f ( -name 'mailcap'  -o 
                   -name '.mailcap' ) -exec egrep 'runexec|runtask' {} 
                   /dev/null ;

        This command will find all files on a system that:
            are only in the local file system (/ -local)
            are regular files (-type f)
            have the name "mailcap" (-name 'mailcap') or the name ".mailcap"

        Once found, those files will be searched for the string "runexec" or
        "runtask" (-exec egrep 'runexec|runtask' {}) and have their path names
        printed .

        The addition of /dev/null as an argument causes egrep to list the
        full pathname of any file containing the string, rather than just the

        Edit the files that have the pathnames printed and remove any
        vulnerable runtask/runexec mailcap entries.

      5) Return to previous level.

                # exit

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

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

   IRIX 3.x          no
   IRIX 4.x          no
   IRIX 5.0.x        no
   IRIX 5.1.x        no
   IRIX 5.2          no
   IRIX 5.3          no
   IRIX 6.0.x        no
   IRIX 6.1          no
   IRIX 6.2          no
   IRIX 6.3          yes           3068
   IRIX 6.4          yes           2339
   IRIX 6.5          no

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

The SGI anonymous FTP site is sgigate.sgi.com ( or its
mirror, ftp.sgi.com.   Security information and patches can be found
in the ~ftp/security and ~ftp/patches directories, respectfully.

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

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

Filename:                 README.patch.3068
Algorithm #1 (sum -r):    54529 8 README.patch.3068
Algorithm #2 (sum):       33465 8 README.patch.3068
MD5 checksum:             E91EB7C7124D8A40DD81DD1CB8CC9DA2

Filename:                 patchSG0003068
Algorithm #1 (sum -r):    54264 2 patchSG0003068
Algorithm #2 (sum):       7687 2 patchSG0003068
MD5 checksum:             6EE55314047752A8B7BFA96EB551DE9F

Filename:                 patchSG0003068.idb
Algorithm #1 (sum -r):    31861 2 patchSG0003068.idb
Algorithm #2 (sum):       13383 2 patchSG0003068.idb
MD5 checksum:             5ACBB5E60F27283E8099C0F310E3BBC9

Filename:                 patchSG0003068.netscape_gold_sw
Algorithm #1 (sum -r):    07593 20 patchSG0003068.netscape_gold_sw
Algorithm #2 (sum):       3826 20 patchSG0003068.netscape_gold_sw
MD5 checksum:             893D690FA20C0AC4E6E4B7E67465B0E2

Filename:                 patchSG0003068.netscape_sw
Algorithm #1 (sum -r):    04774 6 patchSG0003068.netscape_sw
Algorithm #2 (sum):       24847 6 patchSG0003068.netscape_sw
MD5 checksum:             B6FD69352794F52288D536320CBB4A77

Filename:                 README.patch.2339
Algorithm #1 (sum -r):    11695 8 README.patch.2339
Algorithm #2 (sum):       21823 8 README.patch.2339
MD5 checksum:             114563D0D67F80E371C71EF3E6262900

Filename:                 patchSG0002339
Algorithm #1 (sum -r):    37814 2 patchSG0002339
Algorithm #2 (sum):       40753 2 patchSG0002339
MD5 checksum:             E0B519F8ECD83396E29DFE07DF23517E

Filename:                 patchSG0002339.idb
Algorithm #1 (sum -r):    59311 2 patchSG0002339.idb
Algorithm #2 (sum):       54667 2 patchSG0002339.idb
MD5 checksum:             8E39530FD44C9087F0C07B1F75043764

Filename:                 patchSG0002339.netscape_gold_sw
Algorithm #1 (sum -r):    39233 20 patchSG0002339.netscape_gold_sw
Algorithm #2 (sum):       53498 20 patchSG0002339.netscape_gold_sw
MD5 checksum:             7FF56E22472B0797499920BAAB8CA9C5

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

Silicon Graphics wishes to thank the CERT Coordination Center, and
AUSCERT 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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