Sun Solaris kcms_configure Arbitrary File Corruption Vulnerability

iDEFENSE Security Advisory 02.23.05
www.idefense.com/application/poi/display?id=206&type=vulnerabilities
February 23, 2005

I. BACKGROUND

The kcms_configure utility is part of the Kodak Color Management System
(KCMS) package that is included with Solaris.  It is installed setuid
root by default. 

II. DESCRIPTION

Local exploitation of a race condition in the Kodak Color Management
System's kcms_configure script packaged with Sun Microsystems Inc.
Solaris operating system can allow for the corruption of arbitrary files
on the system.

The problem specifically exists due to logging errors within
kcms_configure, a set user id (setuid) root script. The file
KCS_ClogFile will be written to if it exists in the current directory.
Due to a lack of sanity checking a local attacker can redirect log file
output to an arbitrary file on the system through the usage of symbolic
links. By specifying an invalid monitor profile argument the attacker
can force an error log entry to be written.

III. ANALYSIS

Successful exploitation allows local attackers to corrupt arbitrary
files on the system. Attackers can use this ability to append to
important system files, possibly resulting in a denial of service or
local privilege elevation.

IV. DETECTION

iDEFENSE has confirmed the existence of this vulnerability in Sun
Solaris versions 8 and 9. It is suspected that previous versions are
also vulnerable. It has been reported that Solaris 10 pre-release is
also vulnerable.

V. WORKAROUND

Remove the setuid bit from kcms_configure:
    
    # chmod -s /usr/openwin/bin/kcms_configure 

VI. VENDOR RESPONSE

This issue is addressed in Sun Alert ID #57706 available at:

http://www.sunsolve.sun.com/search/printfriendly.do?assetkey=1-26-57706-
1

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
names CAN-2004-0481 to these issues. This is a candidate for inclusion
in the CVE list (http://cve.mitre.org), which standardizes names for
security problems.

VIII. DISCLOSURE TIMELINE

04/27/2004    Initial vendor notification
04/27/2004    Initial vendor response
02/23/2005   Public disclosure

IX. CREDIT

iDEFENSE Labs is credited with this discovery.

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X. LEGAL NOTICES

Copyright (c) 2005 iDEFENSE, Inc.

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Disclaimer: The information in the advisory is believed to be accurate
at the time of publishing based on currently available information. Use
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