CERT-SEI

SGI IRIX Help Vulnerability

Original issue date: August 11, 1994
Last revised: September 23, 1997
Updated copyright statement

A complete revision history is at the end of this file.

The CERT Coordination Center has received information about a vulnerability in the Silicon Graphics, Inc. IRIX operating system, versions 5.1.x and 5.2. This vulnerability enables users to gain unauthorized root access. To exploit the vulnerability, a person must log into an account on the system or have physical access to the system console.

SGI has developed a patch for the vulnerability. Because the vulnerability has been widely discussed in public forums on the Internet, we recommend that you install the patch as soon as possible. Section III below contains instructions for obtaining the patch, along with a workaround you can use until you install it.

We will update this advisory as we receive additional information. Please check advisory files regularly for updates that relate to your site.


I. Description

A vulnerability exists in the SGI help system and print manager, enabling users to get unauthorized root access if they can log into an account on the system or get physical access to the system console. The vulnerability is present in the SGI IRIX operating system, versions 5.1.x and 5.2. SGI reports that the problem will be permanently corrected in a future release of IRIX.

In public discussions, the vulnerability has been referred to by various names, including clogin, printer manager, and SGI Help.

II. Impact

Individuals with accounts on the system or physical access to the system console can obtain root access.

III. Solutions

A. For IRIX 5.2

If you are running IRIX 5.2, obtain and install patch65 according to the instructions provided. These instructions can be found in the "relnotes.patchSG0000065" file in the patch65.tar file (see below).

To install this patch successfully, you need to have the latest SGI "inst" program installed (this is available as patch00 or patch34).

SGI has provided instructions for determining if the new install program is on your system. We have placed these in an appendix at the end of this advisory.

These patches are available by anonymous FTP from ftp.sgi.com and from sgigate.sgi.com in the "/security" directory.

         Filename           patch65.tar
         Standard Unix Sum  63059 1220
         System V Sum       15843 
         MD5                af8c120f86daab9df74998b31927e397


         Filename           patch34.tar.Z
        Standard Unix Sum  11066 15627
        System V Sum      1674 31253
        MD5                2859d0debff715c5beaccd02b6bebded
Patches are available on CD. Contact your nearest SGI service provider for distribution.

B. For IRIX 5.1.x

If you are running versions 5.1.x, SGI recommends that you upgrade to version 5.2, if possible, and then follow the instructions in Section III.A. above. If you cannot upgrade to 5.2, see the workaround instructions in III.C.

C. Workaround

If you cannot install the patches or are delayed in obtaining them, SGI recommends removing the help subsystem using the following command (as root):
# versions remove sgihelp.sw.eoe
PLEASE NOTE: Removal of this subsystem will affect other installed software that use the SGI Help system. After the removal, certain help functions from within applications will return non-fatal error messages about the missing subsystem.

At a later date, when the patch can be installed on the system, you will need to re-install the previously removed SGI Help software prior to installing patch65. This can be found on your original software distribution (CD labeled as IRIX 5.2). As root, use the command:

                # inst -f /CDROM/dist/sgihelp
                Inst> install sgihelp.sw.eoe
                Inst> go
The installation documentation provides further information.

Appendix

There are three patches related to this issue - patch00, patch34, and patch65.

Patch34 is an update to patch00 which modifies the "inst" program to be able to handle patch updates. At least one of patch00 or patch34 is required to be installed before installing patch65. To determine if the new inst program is already installed on your system, the following command can be issued:


 # versions patch\*
        I = Installed, R = Removed

           Name                 Date      Description

        I  patchSG0000034       08/10/94  Patch SG0000034
        I  patchSG0000034.eoe1_sw 08/10/94 IRIX Execution Environment Software
        I  patchSG0000034.eoe1_sw.unix 08/10/94 IRIX Execution Environment

If patchSG0000000 or patchSG0000034 (as seen above) is loaded, then it is only necessary to download patch65 as described in the advisory. This is important since patch34 is rather large (16MB).

Otherwise, download both patch34 and patch65. Install patch34 first, then patch65. To install patch34, uncompress and untar "patch34.tar.Z" and follow the instructions in the "README.FIRST" file.

These patches are available by anonymous FTP from ftp.sgi.com in the "security" directory:


        # versions patch\*
        I = Installed, R = Removed

           Name                 Date      Description

        I  patchSG0000034       08/10/94  Patch SG0000034
        I  patchSG0000034.eoe1_sw 08/10/94 IRIX Execution Environment Software
        I  patchSG0000034.eoe1_sw.unix 08/10/94 IRIX Execution Environment


The CERT Coordination Center wishes to thank Silicon Graphics, Inc., for their cooperation in responding to this problem and members of the AUSCERT and CIAC response teams for their contributions to this advisory.


Copyright 1994,1996 Carnegie Mellon University.


Revision History
Sep. 23, 1997  Updated copyright statement
Aug. 30, 1996  Information previously in the README was inserted
               into the advisory.