Public Vulnerability Reports

QNX Neutrino RTOS phgrafx Command Buffer Overflow



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 buffer overflow in QNX Neutrino RTOS's (QNX)
'phgrafx' 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 'phgrafx'. A
string larger than approximately 1,000 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


Successful exploitation provides local attackers with super-user
privileges on the affected system allowing for complete control.


iDefense has confirmed the existence of these vulnerabilities in QNX
Neutrino RTOS version 6.2.1. Earlier versions are suspected to be
susceptible to exploitation as well.


Clear the set user id or execute bits from the affected binary or remove
it entirely.


This issue has been corrected in QNX Neutrino 6.3.0 Service Pack 2.

QNX customers can download this patch from


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


08/24/2004 Initial vendor notification
02/07/2006 Public disclosure


Knud Hojgaard ( is credited with this

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