Date: Wed, 21 Oct 1998 16:07:49 -0700
From: RSI Advise <advise@ENIGMA.REPSEC.COM>
To: BUGTRAQ@netspace.org
Subject: RSI.0010.10-21-98.IRIX.AUTOFSD

RSI.0010.10-21-98.IRIX.AUTOFSD



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                   Repent Security Incorporated, RSI
                       [ http://www.repsec.com ]


                       *** RSI ALERT ADVISORY ***


--- [CREDIT] --------------------------------------------------------------

Mark Zielinski : Discovered the vulnerability, author of the advisory


--- [SUMMARY] -------------------------------------------------------------

Announced:     October 2, 1998
Report code:   RSI.0010.10-21-98.IRIX.AUTOFSD
Report title:  IRIX autofsd

Vulnerability: Please see the details section
Vendor status: SGI contacted on October 2, 1998
Patch status:  No patch is currently available

Platforms:     IRIX 6.2, 6.3, 6.4, 6.5

Reference:     http://www.repsec.com/advisories.html
Impact:        If exploited, an attacker could potentially compromise
               root access locally on your server

NOTE:          IRIX versions 5.3, 6.0, and 6.1 were NOT tested, however
               they could be subject to the same vulnerability.


--- [DETAILS] -------------------------------------------------------------

Description:   Autofsd is an RPC server which answers file system mount
               and umount requests from the autofs file system.  It uses
               local files or name service maps to locate file systems to
               be mounted.

Problem:       Users locally on the system can send requests to the
               autofsd daemon and execute arbitrary commands as the
               superuser.

               Upon receiving a map argument from a client,
               the server will attempt to verify if it is executable
               or not.  If autofsd determines the map has an executable
               flag, the server will append the client's key and attempt
               to execute it.

               By sending a map name that is executable on the server,
               and a key beginning with a semicolon or a newline followed
               by a command, unprivileged users can execute arbitrary
               commands as the superuser.

               The problem occurs when the server appends the key
               to the map and attempts to execute it by calling
               popen.

               Since popen executes the map and key you specify by
               invoking a shell, it is possible to force it into executing
               commands that were not meant to be executed.


--- [FIX] -----------------------------------------------------------------

Solution:      Do not run autofsd until a patch is released for the
               version of IRIX you are running.


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Repent Security Incorporated (RSI)
13610 N. Scottsdale Rd.
Suite #10-326
Scottsdale, AZ 85254

E-Mail: advise@repsec.com
FTP: ftp://ftp.repsec.com
WWW: http://www.repsec.com

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