QNX Neutrino RTOS phfont Race Condition Vulnerability
iDefense Security Advisory 02.07.06
http://www.idefense.com/intelligence/vulnerabilities/display.php?id=383
February 7, 2006
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 race condition vulnerability in QNX Neutrino
RTOS's (QNX) phfont command allows attackers to gain root privileges.
QNX Neutrino RTOS is a real-time operating system designed for use in
embedded systems. The problem specifically exists because phfont spawns
another command, phfontphf, without proper sanity checking. A local
attacker can create a malicious replacement for this command and cause
it to be executed in place of the original by manipulating the PHFONT
and PHOTON2_PATH environment variables. phfont is installed set user id
root by default.
III. ANALYSIS
Successful exploitation provides local attackers with super user
privileges on the affected system, allowing for complete control.
IV. DETECTION
iDefense has confirmed the existence of these vulnerabilities in QNX
Neutrino RTOS version 6.2.1. Earlier versions are also suspected to be
susceptible to exploitation.
V. WORKAROUND
Clear the set user ID or execute bits from the affected binary or remove
it entirely.
VI. VENDOR RESPONSE
The vendor has not responded to communication regarding this issue.
VII. CVE INFORMATION
A Mitre Corp. Common Vulnerabilities and Exposures (CVE) number has not
been assigned yet.
VIII. DISCLOSURE TIMELINE
09/29/2004 Initial vendor notification
02/07/2006 Public disclosure
IX. CREDIT
Knud Hojgaard (http://kokanin.dtors.net) 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.
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