Public Vulnerability Reports

IBM AIX netpmon Local Buffer Overflow Vulnerability



The netpmon program is a setuid root application, installed by default
under multiple versions of IBM AIX, which can be used to monitor
activity and report statistics on network I/O and network-related CPU


Local exploitation of a buffer overflow vulnerability in the netpmon
command included by default in multiple versions of IBM Corp.'s AIX
Operating System could allow for arbitrary code execution as the root

The vulnerability specifically exists due to an unbounded string copying
operation into stack memory. When provided with a long argument to the
-O option (the ReportType option), the netpmon process will overwrite
stack memory. This allows for the execution of arbitrary code by
overwriting the saved return address.


Exploitation of this vulnerability is simple for a skilled attacker,
however gid "system" is required in order to execute the vulnerable
binary. Successful exploitation yields root access to the system.


iDEFENSE has confirmed the existence of this vulnerability in IBM AIX
version 5.2. It is suspected that previous versions are also vulnerable.


Only allow trusted users local access to security critical systems; only
allow trusted users access to the "system" group. Alternately, remove
the setuid bit from netpmon using chmod u-s /usr/bin/netpmon


Vendor advisories for this issue are available at:

For AIX 5.1:

For AIX 5.2:

For AIX 5.3:


 The Common Vulnerabilities and Exposures (CVE) project has assigned the
names CAN-2005-0263 these issues. This is a candidate for inclusion
in the CVE list (, which standardizes names for
security problems.


12/21/2004   Initial vendor notification
01/07/2004   Initial vendor response
02/10/2005   Coordinated public disclosure


iDEFENSE Labs is credited with this discovery

Get paid for vulnerability research


Copyright © 2005 Verisign, Inc.

Permission is granted for the redistribution of this alert
electronically. It may not be edited in any way without the express
written consent of iDEFENSE. If you wish to reprint the whole or any
part of this alert in any other medium other than electronically, please
email for permission.

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.