Public Vulnerability Reports

SCO Openserver backupsh 'Home' Buffer Overflow Vulnerability



SCO OpenServer is a UNIX-like operating system for x86 platforms.


Local exploitation of a buffer overflow vulnerability in The SCO Group
Inc.'s Openserver operating system could allow an attacker to gain
access to the backup group.

The backupsh utility is a standard binary distributed with the Openserver
platform. The vulnerability specifically exists because of a lack of
bounds checking on the value given to the "HOME" environment variable.
Local attackers can supply a specially crafted string to overflow a
stack buffer and execute arbitrary code with group backup privileges.


Successful exploitation of this vulnerability will result in execution
of arbitrary code with permissions of the running process. The binary is
setgid backup by default and can be used by attackers with a local
account to gain backup privileges.


iDEFENSE has confirmed the existence of this vulnerability in SCO
Openserver 5.0.7. It is suspected that earlier versions are also


As a workaround solution, remove the setgid bit from the backupsh binary
until a vendor patch can be applied.

# chmod g-s /opt/K/SCO/Unix/5.0.7Hw/usr/lib/sysadm/backupsh


The vendor has released the following advisory for this issue:


The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2005-2926 to this issue. This is a candidate for inclusion in
the CVE list (, which standardizes names for
security problems.


09/08/2005   Initial vendor notification
09/09/2005   Initial vendor response
10/24/2005   Public disclosure


iDEFENSE Labs is credited with the discovery of this vulnerability.

Get paid for vulnerability research

Free tools, research and upcoming events


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.