Public Vulnerability Reports

IBM DB2 Universal Database Directory Traversal Vulnerability

08.16.07

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/

DESCRIPTION

Local exploitation of a directory traversal vulnerability in IBM Corp.'s DB2 Universal Database allows attackers to cause a denial of service (DoS) condition or elevate privileges to root.

Some DB2 binaries that are installed setuid-root will save event information to a log file. When creating the full path to the destination file, an environment variable is concatenated with "/tmp/". Since there is no checking for path traversal strings, such as "../", within the environment variable, an attacker is able to create arbitrary files on the system.

ANALYSIS

Exploitation allows local attackers to gain root privileges.

It should be noted that attackers do not appear to have any control over the contents of the data written. As such, privilege escalation can occur in combination with a vulnerability that relies on the ability to create a specially crafted file name. Denying service to the machine is trivial by writing to /etc/nologin or corrupting other critical system files.

DETECTION

iDefense confirmed the existence of this vulnerability 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.

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.

VENDOR RESPONSE

IBM Corp. has addressed this vulnerability 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

CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2007-4271 to this issue. This is a candidate for inclusion in the CVE list (http://cve.mitre.org/), which standardizes names for security problems.

DISCLOSURE TIMELINE

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

CREDIT

The discoverer of this vulnerability wishes to remain anonymous.

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LEGAL NOTICES

Copyright © 2007 Verisign, 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 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.