-----BEGIN PGP SIGNED MESSAGE-----

===========================================================================
CA-91:14                        CERT Advisory
                              August 26, 1991
                    SGI "IRIX" /usr/sbin/fmt Vulnerability

- ---------------------------------------------------------------------------

The Computer Emergency Response Team/Coordination Center (CERT/CC) has
received information concerning a vulnerability of mail messages in Silicon
Graphics Computer Systems' IRIX versions prior to 4.0 (this includes all
3.2 and 3.3.* versions).  This problem has been fixed in version 4.0.

Information regarding the exploitation of this vulnerability is inherently
disclosed by any discussion of the problem (including this Advisory) so
we recommend taking immediate action. Until you are able to apply the patch,
mail at your site is vulnerable to being read by any ordinary user logged
in at that site.

Silicon Graphics has provided the enclosed patch instructions.

- ---------------------------------------------------------------------------

I.   DESCRIPTION:

    A vulnerability exists such that IRIX pre-4.0 (e.g., 3.3.3) systems
    with the basic system software ("eoe1.sw.unix") installed can allow
    unauthorized read access to users' mail messages, by exploiting a
    configuration error in a standard system utility. Due to the ease
    of exploiting this vulnerability and the simplicity of the corrective
    action, the CERT/CC urges all sites to install the patch given below.

II.  IMPACT:

    Anyone who can log in on a given IRIX pre-4.0 (3.2, 3.3, 3.3.*) system
    can read mail messages which have been delivered to any other user on
    that same system.

III. SOLUTION:

    As "root", execute the following commands:

       chmod 755 /usr/sbin/fmt
       chown root.sys /usr/sbin/fmt

    If system software should ever be reloaded from a 3.2 or 3.3.*
    installation tape or from a backup tape created before the patch
    was applied, repeat the above procedure immediately after the software
    has been reloaded, before enabling logins by normal users.

    [Fixed in IRIX 4.0.]


- ---------------------------------------------------------------------------
The CERT/CC would like to thank Silicon Graphics for bringing this
vulnerability and solution to our attention.
- ---------------------------------------------------------------------------

If you believe that your system has been compromised, contact CERT/CC via
telephone or e-mail.

Computer Emergency Response Team/Coordination Center (CERT/CC)
Software Engineering Institute
Carnegie Mellon University
Pittsburgh, PA 15213-3890

Internet E-mail: [email protected]
Telephone: 412-268-7090 24-hour hotline:
          CERT/CC personnel answer 7:30a.m.-6:00p.m. EST,
          on call for emergencies during other hours.

Past advisories and other computer security related information are available
for anonymous ftp from the cert.org (192.88.209.5) system.


-----BEGIN PGP SIGNATURE-----
Version: 2.6.2

iQCVAwUBMaMwv3VP+x0t4w7BAQGcMAQAqqS6GkJCvU6raANhmIWk4P4yYUHVT9nH
LCKMUQQCDS6GC52kADRI1346yx0DnvWM4kysn9DHWfUkM3dllYpTOguhqRreN/y9
OwL9z928gWQrfOvE24Ldf+HKgdP4tQCjK3DCr990quw4Rp9iNgiexhEMzOSmCueC
4n3VjVPSZ/U=
=YkZm
-----END PGP SIGNATURE-----