SCO Unixware Setuid 'uidadmin' Scheme Buffer Overflow Vulnerability iDefense Security Advisory 12.12.05 www.iDefense.com/application/poi/display?id=350&type=vulnerabilities December 12, 2005 I. BACKGROUND SCO Unixware is a Unix operating system that runs on many OEM platforms. II. DESCRIPTION Local exploitation of a buffer overflow vulnerability in the uidadmin binary included in multiple versions of The SCO Group Inc.'s Unixware allows attackers to gain root privileges. The vulnerability specifically exists because of a failure to check the length of user specified file input. If the user prepares a file longer than 1,600 bytes and supplies the path to that file using the "-S" option of uidadmin, a stack based buffer overflow occurs. This leads to the execution of arbitrary code with root privileges, as uidadmin is setuid root by default. III. ANALYSIS Successful exploitation of this vulnerability requires that a user have local access to the system. This would allow the user to gain super user privileges. IV. DETECTION iDefense has confirmed the existence of this vulnerability in SCO Unixware versions 7.1.3 and 7.1.4. All previous versions of SCO Unixware are suspected to be vulnerable. V. WORKAROUND Remove the setuid bit from the ppp binary: chmod u-s /unixware/usr/bin/uidadmin VI. VENDOR RESPONSE The vendor has released the following update to address this vulnerability: ftp://ftp.sco.com/pub/updates/UnixWare/SCOSA-2005.54 VII. CVE INFORMATION The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2005-3903 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 10/12/2005 Initial vendor notification 10/13/2005 Initial vendor response 12/12/2005 Coordinated public disclosure IX. CREDIT iDefense Labs is credited with the discovery of this vulnerability. Get paid for vulnerability research http://www.iDefense.com/poi/teams/vcp.jsp Free tools, research and upcoming events http://labs.iDefense.com X. LEGAL NOTICES Copyright © 2005 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 email customerservice (at) iDefense (dot) com [email concealed] 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.