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). 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 firstname.lastname@example.org 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.