IBM DB2 Universal Database Directory Creation Vulnerability 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 a directory creation vulnerability in IBM Corp.'s DB2 Universal Database could allow attackers to elevate privileges to the superuser. This vulnerability exists due to insecure directory creation within setuid-binaries included with DB2. While creating specific directory structures, attacker created symbolic links will be followed. This allows world-writable directories to be created anywhere on the file system. III. ANALYSIS Exploitation allows local attackers to gain root privileges. In order to execute arbitrary code, an attacker could create a world-writable locale directory. By creating a specially crafted localized message file, the attacker can cause a format string of their choosing to be passed to a function in the printf(3) family. Using known format string exploitation techniques, an attacker can then execute arbitrary code as root. This should not be considered the only way to gain root privileges with this vulnerability. However, iDefense has confirmed this method in lab tests. IV. 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. 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 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 VII. CVE INFORMATION The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2007-4273 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 The discoverer of this vulnerability wishes to remain anonymous. Get paid for vulnerability research http://labs.idefense.com/methodology/vulnerability/vcp.php Free tools, research and upcoming events http://labs.idefense.com/ X. LEGAL NOTICES Copyright © 2007 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 e-mail email@example.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.