I. BACKGROUND
SCO Unixware is a Unix operating system that runs on many OEM platforms.
II. DESCRIPTION
Local exploitation of a buffer overflow vulnerability in the uidadmin
binary included in multiple versions of The SCO Group Inc.'s Unixware
allows attackers to gain root privileges.
The vulnerability specifically exists because of a failure to check the
length of user specified file input. If the user prepares a file longer
than 1,600 bytes and supplies the path to that file using the "-S"
option of uidadmin, a stack based buffer overflow occurs. This leads to
the execution of arbitrary code with root privileges, as uidadmin is
setuid root by default.
III. ANALYSIS
Successful exploitation of this vulnerability requires that a user have
local access to the system. This would allow the user to gain super user
privileges.
IV. DETECTION
iDEFENSE has confirmed the existence of this vulnerability in SCO
Unixware versions 7.1.3 and 7.1.4. All previous versions of SCO Unixware
are suspected to be vulnerable.
V. WORKAROUND
Remove the setuid bit from the ppp binary:
chmod u-s /unixware/usr/bin/uidadmin
VI. VENDOR RESPONSE
The vendor has released the following update to address this
vulnerability:
ftp://ftp.sco.com/pub/updates/UnixWare/SCOSA-2005.54
VII. CVE INFORMATION
The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2005-3903 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org), which standardizes names for
security problems.
VIII. DISCLOSURE TIMELINE
10/12/2005 Initial vendor notification
10/13/2005 Initial vendor response
12/12/2005 Coordinated public disclosure
IX. CREDIT
iDEFENSE Labs is credited with the discovery of this vulnerability.
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X. LEGAL NOTICES
Copyright © 2005 iDEFENSE, 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 customerservice@idefense.com 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.
