IBM DB2 Universal Database Multiple Race Condition Vulnerabilities

iDefense Security Advisory 08.16.07
http://labs.idefense.com/intelligence/vulnerabilities/
Aug 16, 2007

I. BACKGROUND

IBM Corp.'s DB2 Universal Database product is a large database server
product commonly used for high end databases. For more information,
visit the following URL.

http://ibm.com/db2/

II. DESCRIPTION

Local exploitation of multiple race condition vulnerabilities in IBM
Corp.'s DB2 Universal Database could allow attackers to elevate
privileges to the superuser.

These vulnerabilities are due to insufficient checking being performed
while handling files with elevated privileges. In each case, a race
condition exists between a check to see if an existing file is a
symbolic link and modifying it. By quickly and repeatedly removing and
recreating the file as a symbolic link, an attacker could modify
arbitrary files with root privileges.

III. ANALYSIS

Exploitation allows local attackers to gain root privileges.

Depending on the specific vulnerability, the attacker may have little or
no control over the contents of data written to the file. In most cases,
this does not significantly impact exploitation since file permissions
allow the file to be written to by the attacker.

IV. DETECTION

iDefense confirmed the existence of these vulnerabilities in version 9.1
Fix Pack 2 of IBM Corp.'s DB2 Universal Database installed on a Linux
system. All prior versions, as well as builds for other UNIX-based
operating systems, are suspected to be vulnerable.

V. WORKAROUND

Setting more strict permissions on the DB2 instance directory can help
mitigate some of these vulnerabilities. Removing the setuid-bit from
all programs included with DB2 can also help mitigate exposure. Note,
these configuration changes have not been thoroughly tested and may
cause adverse behavior.

VI. VENDOR RESPONSE

IBM Corp. has addressed these vulnerabilities by releasing V9 Fix Pack 3
and version V8 FixPak 15 of its Universal Database product. More
information can be found at the following URLs.

V8: http://www-1.ibm.com/support/docview.wss?uid=swg21256235
V9: http://www-1.ibm.com/support/docview.wss?uid=swg21255572

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2007-4270 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

03/22/2007  Initial vendor notification
03/23/2007  Initial vendor response
08/16/2007  Coordinated public disclosure

IX. CREDIT

These vulnerabilities were discovered by an anonymous researcher and
Joshua J. Drake (iDefense Labs).

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X. LEGAL NOTICES

Copyright © 2007 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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