I. BACKGROUND
QNX Software Systems Ltd.'s Neutrino RTOS (QNX) is a real-time operating
system designed for
use in embedded systems. More information is
available at:
http://www.qnx.com/products/rtos/
II. DESCRIPTION
Local exploitation of a buffer overflow in QNX Neutrino RTOS's (QNX)
'su' command allows
attackers to gain root privileges. The problem
specifically exists in the parsing of a long
string passed as the first
argument to the set user id (setuid) binary 'su'. The 'su' command is
intended for running commands under a substitute user or group id. A
string larger then
approximately 4000 bytes causes a stack overflow
directly overwriting the stored return address
and allowing an attacker
to seize CPU control and eventually execute arbitrary code under
root
privileges.
III. ANALYSIS
Any authenticated local attacker can exploit this vulnerability to gain
super-user (root)
privileges on the affected system.
IV. DETECTION
iDefense has confirmed the existence of these vulnerabilities in QNX
Neutrino RTOS version
6.2.0. Earlier versions are suspected to be
susceptible to exploitation as well.
V. WORKAROUND
Clear the set user id or execute bits from the affected binary or remove
it entirely.
VI. VENDOR RESPONSE
This issue has been corrected in QNX Momentics 6.3.0 SP3 and later
versions. A patch is also available for 6.3.0, 6.3.0 SP1, and 6.3.0 SP2
(Patch ID:270). Please contact your QNX representative, or visit
http://www.qnx.com/account/login.html to obtain
these patches.
VII. CVE INFORMATION
A Mitre Corp. Common Vulnerabilities and Exposures (CVE) number has not
been assigned yet.
VIII. DISCLOSURE TIMELINE
06/04/2004 Initial vendor notification
02/07/2006 Public disclosure
IX. CREDIT
Texonet (www.texonet.com) is credited with this discovery.
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X. LEGAL NOTICES
Copyright © 2006 iDefense, Inc.
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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.
