SGI IRIX inpview Design Error Vulnerability
iDEFENSE Security Advisory 01.13.05
www.idefense.com/application/poi/display?id=182&type=vulnerabilities
January 13, 2005
I. BACKGROUND
The inpview program is a setuid root application that is included in the
InPerson networked multimedia conferencing tool. InPerson networked
multimedia conferencing tool is included in SGI IRIX.
II. DESCRIPTION
Local exploitation of a design error vulnerability in the inpview
command included in multiple versions of Silicon Graphics Inc.'s IRIX
could allow for arbitrary code execution as the root user.
The vulnerability specifically exists due to the fact that inpview
trusts the user environment and does not drop privileges. When the
environment variable SUN_TTSESSION_CMD is something such as "cp /bin/jsh
/tmp/jsh;chmod 6755 /tmp/jsh;killall -9 inpview," the chain of commands
will be executed with root permissions, thus allowing a regular user to
drop a setuid and setgid shell to /tmp.
III. ANALYSIS
All that is required to exploit this vulnerability is a local account
and an open X display, which could be the attacker's home machine or
another compromised system. Exploitation does not require any knowledge
of application internals, making privilege escalation trivial, even for
unskilled attackers.
IV. DETECTION
iDEFENSE has confirmed the existence of this vulnerability in SGI IRIX
version 6.5.9 (feature) and 6.5.22 (maintenance). It is suspected that
previous and later versions of both the feature and maintenance
revisions of IRIX 6.5 are also vulnerable.
V. WORKAROUND
Only allow trusted users local access to security critical systems.
Alternately, remove the setuid bit from inpview:
chmod u-s /usr/lib/InPerson/inpview
VI. VENDOR RESPONSE
Support for the InPerson product did not extend beyond 02/2002 as noted
in the following publication:
techpubs.sgi.com/library/manuals/4000/007-4526-001/pdf/007-4526-001.pdf
As a result, no patch will be issued for this vulnerability.
VII. CVE INFORMATION
A Mitre Corp. Common Vulnerabilities and Exposures (CVE) number has not
been assigned yet.
VIII. DISCLOSURE TIMELINE
01/06/2005 Initial vendor notification
01/07/2005 Initial vendor response
01/13/2005 Public disclosure
IX. CREDIT
iDEFENSE Labs is credited with this discovery.
Get paid for vulnerability research
http://www.idefense.com/poi/teams/vcp.jsp
X. LEGAL NOTICES
Copyright (c) 2004 iDEFENSE, Inc.
Permission is granted for the redistribution of this alert
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Disclaimer: The information in the advisory is believed to be accurate
at the time of publishing based on currently available information. Use
of the information constitutes acceptance for use in an AS IS condition.
There are no warranties with regard to this information. Neither the
author nor the publisher accepts any liability for any direct, indirect,
or consequential loss or damage arising from use of, or reliance on,
this information.
