__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Sun Solaris at(1) Command Vulnerability [Sun(sm) Alert Notification 50161] April 3, 2003 03:00 GMT Number N-070 ______________________________________________________________________________ PROBLEM: Race condition and argument handling vulnerabilites exist in the at(1) command, which may allow a user to remove any file on the system. PLATFORM: * Solaris 2.6 * Solaris 7 * Solaris 8 * Solaris 9 DAMAGE: If exploited, a local unprivileged user may be able to remove any file on the system. SOLUTION: Apply patch or workaround. ______________________________________________________________________________ VULNERABILITY The risk is MEDIUM. In order to exploit this vulnerability, an ASSESSMENT: attacker would need a legitimate account and permission on the target system to delete files. ______________________________________________________________________________ LINKS: CIAC BULLETIN: http://www.ciac.org/ciac/bulletins/n-070.shtml ORIGINAL BULLETIN: http://www.sunsolve.sun.com/pub-cgi/ retrieve.pl?doc=fsalert%2F50161&zone_32=category%3Asecurity ______________________________________________________________________________ [***** Start Sun(sm) Alert Notification 50161 *****] Sun(sm) Alert Notification Sun Alert ID: 50161 Synopsis: Security Vulnerability with the at(1) Command on Solaris Category: Security Product: Solaris BugIDs: 4776480 Avoidance: Patch State: Resolved Date Released: 30-Jan-2003, 31-Mar-2003 Date Closed: 31-Mar-2003 Date Modified: 31-Mar-2003 1. Impact A local unprivileged user may be able to remove any file on the system due to a security vulnerability in the at(1) command. Sun acknowledges with thanks, Wojciech Purczynski of iSEC Security Research, for bringing this issue to our attention. This issue is described in an iSEC Security Research advisory (see http://isec.pl/vulnerabilities/isec-0008-sun-at.txt). 2. Contributing Factors This issue can occur in the following releases: SPARC Platform Solaris 2.6 without patch 105181-34 Solaris 7 without patch 108319-03 Solaris 8 without patches 109007-09 and 108875-13 Solaris 9 without patch 114135-01 x86 Platform Solaris 2.6 without patch 105182-34 Solaris 7 without patch 108320-03 Solaris 8 without patches 109008-09 and 108876-13 Solaris 9 without patch 114136-01 Notes: Solaris 2.5.1 will not be evaluated regarding a potential impact of the issue described in this Sun Alert document. The Solaris 8 cron/at patches 109007-09 and 109008-09 require the libbsm/c2audit patches 108875-13 and 108876-13 respectively for the correct functioning of the crontab(1) command. Future revisions of the Solaris 8 cron/at patches will contain the libbsm/c2audit binaries and will not require the installation of the libbsm/c2audit patches. 3. Symptoms There are no predictable symptoms that would show the described issue has been exploited, as it depends on what file or files were deleted. Solution Summary Top 4. Relief/Workaround To work around the described issue, the set-user-ID bit can be removed from the at(1) command. However, once the set-user-ID bit is removed the "at" command will no longer function. As root do the following: # chmod u-s /usr/bin/at 5. Resolution This issue is addressed in the following releases: SPARC Platform Solaris 2.6 with patch 105181-34 or later Solaris 7 with patch 108319-03 or later Solaris 8 with patch 109007-09 and 108875-13 or later Solaris 9 with patch 114135-01 or later x86 Platform Solaris 2.6 with patch 105182-34 or later Solaris 7 with patch 108320-03 or later Solaris 8 with patch 109008-09 and 108876-13 or later Solaris 9 with patch 114136-01 or later Change History 31-Mar-2003: State: Resolved Updated Contributing Factors and Resolution sections This Sun Alert notification is being provided to you on an "AS IS" basis. This Sun Alert notification may contain information provided by third parties. The issues described in this Sun Alert notification may or may not impact your system(s). Sun makes no representations, warranties, or guarantees as to the information contained herein. ANY AND ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT, ARE HEREBY DISCLAIMED. BY ACCESSING THIS DOCUMENT YOU ACKNOWLEDGE THAT SUN SHALL IN NO EVENT BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, PUNITIVE, OR CONSEQUENTIAL DAMAGES THAT ARISE OUT OF YOUR USE OR FAILURE TO USE THE INFORMATION CONTAINED HEREIN. This Sun Alert notification contains Sun proprietary and confidential information. It is being provided to you pursuant to the provisions of your agreement to purchase services from Sun, or, if you do not have such an agreement, th! e Sun.com Terms of Use. This Sun Alert notification may only be used for the purposes contemplated by these agreements. Copyright 2000-2003 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, CA 95054 U.S.A. All rights reserved. [***** End Sun(sm) Alert Notification 50161 *****] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of Sun Microsystems, Inc. and iSec for the information contained in this bulletin. _______________________________________________________________________________ CIAC, the Computer Incident Advisory Capability, is the computer security incident response team for the U.S. Department of Energy (DOE) and the emergency backup response team for the National Institutes of Health (NIH). CIAC is located at the Lawrence Livermore National Laboratory in Livermore, California. CIAC is also a founding member of FIRST, the Forum of Incident Response and Security Teams, a global organization established to foster cooperation and coordination among computer security teams worldwide. CIAC services are available to DOE, DOE contractors, and the NIH. CIAC can be contacted at: Voice: +1 925-422-8193 (7x24) FAX: +1 925-423-8002 STU-III: +1 925-423-2604 E-mail: ciac@ciac.org Previous CIAC notices, anti-virus software, and other information are available from the CIAC Computer Security Archive. World Wide Web: http://www.ciac.org/ Anonymous FTP: ftp.ciac.org PLEASE NOTE: Many users outside of the DOE, ESnet, and NIH computing communities receive CIAC bulletins. If you are not part of these communities, please contact your agency's response team to report incidents. Your agency's team will coordinate with CIAC. The Forum of Incident Response and Security Teams (FIRST) is a world-wide organization. A list of FIRST member organizations and their constituencies can be obtained via WWW at http://www.first.org/. This document was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor the University of California nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation or favoring by the United States Government or the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or the University of California, and shall not be used for advertising or product endorsement purposes. 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