iDefense Security Advisory 08.04.09 http://labs.idefense.com/intelligence/vulnerabilities/ Aug 04, 2009 I. BACKGROUND IBM's AIX is a Unix operating system based on System V, which runs on the PowerPC (PPC) architecture. For more information, visit the product web site at the following URL. http://www.ibm.com/systems/power/software/aix/index.html II. DESCRIPTION Local exploitation of an arbitrary file creation vulnerability in IBM Corp.'s Advanced Interactive eXecutive (AIX) Operating System allows attackers to execute arbitrary code with super-user privileges. This vulnerability exists due to the handling of several environment variables. The libC.a library will open files as specified by the "_LIB_INIT_DBG" and "_LIB_INIT_DBG_FILE" variables. The attacker's "umask" will be honored, allowing them to create world-writable files, owned by root, in arbitrary locations on the system. III. ANALYSIS Exploitation of this vulnerability allows attackers to execute arbitrary code with super-user privileges. In order to exploit this vulnerability an attacker must be able to execute a set-uid binary linked with the "libC.a" library. In default installations, several binaries may be executed by any user with a local account; no special group membership is needed. IV. DETECTION iDefense has confirmed the existence of this vulnerability in IBM Corp.'s AIX version 5.3. Other versions may also be affected. V. WORKAROUND iDefense is currently unaware of any effective workaround for this issue. VI. VENDOR RESPONSE IBM has released a patch which addresses this issue. For more information, consult their advisory at the following URL: http://aix.software.ibm.com/aix/efixes/security/libC_advisory.asc VII. CVE INFORMATION A Mitre Corp. Common Vulnerabilities and Exposures (CVE) number has not been assigned yet. VIII. DISCLOSURE TIMELINE 02/25/2009 - Initial Contact 03/03/2009 - Initial Response 08/04/2009 - IBM proposed release date of August 4th, 2009 08/04/2009 - Coordinated public disclosure IX. CREDIT This vulnerability was reported to iDefense by Karol Wiesek. 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 © 2009 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 customerservice@xxxxxxxxxxxx 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.
