From labs-no-reply@idefense.com Thu Apr 7 13:55:04 2005 From: iDEFENSE Labs To: bugtraq@securityfocus.com, vulnwatch@vulnwatch.org Date: Thu, 7 Apr 2005 13:06:57 -0400 Subject: iDEFENSE Security Advisory 04.07.05: SGI IRIX gr_osview File Overwrite Vulnerability SGI IRIX gr_osview File Overwrite Vulnerability iDEFENSE Security Advisory 04.07.05 http://www.idefense.com/application/poi/display?type=vulnerabilities April 7, 2005 I. BACKGROUND The gr_osview application is a setuid root application that provides a graphical display of usage of certain types of operating system resources. It is installed by default under multiple versions of IRIX 6. II. DESCRIPTION Local exploitation of a file overwrite vulnerability in the gr_osview command included in multiple versions of Silicon Graphics Inc.'s IRIX operating system could allow for the overwriting of arbitrary files, regardless of permissions. The vulnerability specifically exists in the way that gr_osview opens user specified files without dropping privileges. When a file is specified using the "-s" option, it will be opened regardless of permissions, and operating system usage information will be written into it. An example follows: user@irix$ gr_osview -s /etc/shadow After execution of that command, the system shadow file will be overwritten with system usage information. With a damaged shadow file, users will no longer be able to log on remotely or locally. III. ANALYSIS All that is required to exploit this vulnerability is a local account and an open X display, which could be the attacker's home machine or another compromised computer. Exploitation does not require any knowledge of application internals, making exploitation trivial, even for unskilled attackers. IV. DETECTION iDEFENSE has confirmed the existence of this vulnerability in SGI IRIX version 6.5.22 (maintenance). It is suspected that previous and later versions of both the feature and maintenance revisions of IRIX 6.5 are also vulnerable. V. WORKAROUND Only allow trusted users local access to security-critical systems. Alternately, remove the setuid bit from inpview using: chmod u-s /usr/sbin/gr_osview VI. VENDOR RESPONSE This vulnerability has been addressed in SGI BUG 930890. Related security advisories are available at: http://www.sgi.com/support/security/advisories.html Related patches are available at: http://www.sgi.com/support/security/patches.html ftp://patches.sgi.com/support/free/security/patches/ VII. CVE INFORMATION The Common Vulnerabilities and Exposures (CVE) project has assigned the names CAN-2005-0465 to these issues. This is a candidate for inclusion in the CVE list (http://cve.mitre.org), which standardizes names for security problems. VIII. DISCLOSURE TIMELINE 02/18/2005 Initial vendor notification 02/23/2005 Initial vendor response 04/07/2005 Coordinated public disclosure IX. CREDIT The discoverer of this vulnerability wishes to remain anonymous. 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 (c) 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@idefense.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.