Public Vulnerability Reports

IBM AIX muxatmd Buffer Overflow Vulnerability



IBM's AIX is a Unix operating system based on System V, which runs on the PowerPC (PPC) architecture. For more information, visit the product website at the following URL.


Local exploitation of a buffer overflow vulnerability in IBM Corp.'s Advanced Interactive eXecutive (AIX) could allow an attacker to gain root privileges.

The set-uid root binary "muxatmd" concatenates the calling program name with the static string ".pid". The destination buffer passed to the function call used for concatenation is a static-sized stack buffer. Since no bounds checking is performed, a stack-based buffer overflow can occur when a long program name is given.


Exploitation of this issue allows an attacker to execute arbitrary code as root. An attacker would need to construct a malicious application that runs the "muxatmd" program with a malformed parameter.


iDefense has confirmed the existence of this vulnerability in IBM Corp.'s AIX version 5.3 (5300-09-02-0849). Other versions may also be affected.


Removing the set-uid bit from the "/usr/sbin/muxatmd" binary will provide a workaround for this issue. However, this will make the program unusable for non-root users.


IBM has released a patch which addresses this issue. For more information, consult their advisory at the following URL:


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


12/16/2008 - Initial Vendor Notification
12/16/2008 - Requested PoC
01/06/2009 - PoC Sent
04/15/2009 - Coordinated Public Disclosure


The discoverer of this vulnerability wishes to remain anonymous.

Get paid for vulnerability research

Free tools, research and upcoming events


Copyright © 2009 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 e-mail customer service 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.