Public Vulnerability Reports

QNX RTOS 6.3.0 rc.local Insecure File Permissions Vulnerability



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:


Local exploitation of a design vulnerability in QNX Software Systems QNX
Realtime Operating System (RTOS) allows attackers to execute arbitrary
commands with root privileges.

The problem specifically exists because QNX RTOS 6.3.0 ships with world
writable permissions on the file /etc/rc.d/rc.local. This file is parsed
and executed with root privileges upon startup. An attacker can insert
commands into this file which will then be executed once the operating
system is restarted.


Successful exploitation allows local attackers to execute arbitrary
commands with root privileges. This vulnerability when combined with a
local system-wide denial of service vulnerability allows an attacker to
gain immediate root privileges.


iDefense has confirmed the existence of this vulnerability in QNX RTOS
version 6.3.0. Version 6.0 was also tested and found to not be


Set more restrictive permissions on the rc.local file:

chmod 644 /etc/rc.d.rc.local


This issue has been corrected in QNX Momentics 6.3.0 SP2 and later versions. Please contact your QNX representative, or visit to obtain the above release.


A Mitre Corp. Common Vulnerabilities and Exposures (CVE) number has not
been assigned yet.


12/24/2004 Initial vendor notification
02/07/2006 Public disclosure


The discoverer of this vulnerability wishes to remain anonymous.

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