__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN pcAnywhere Denial of Service, abnormal server connection March 5, 2001 22:00 GMT Number L-055 ______________________________________________________________________________ PROBLEM: A software error exists in the Symantec pcAnywhere remote control solution. PLATFORM: pcAnywhere Version 9.x and 10.x DAMAGE: An abnormal number of random characters sent to the pcAnywhere listening port, immediately upon connection, causes communications to fail. The server has to be restarted to clear the port. The result is an immediate denial of service (DoS) to the affected server. The vulnerability has the potential to allow an intruder to run programs on a system. SOLUTION: Immediately apply the patch as directed by the security alert. ______________________________________________________________________________ VULNERABILITY The risk is MEDIUM. A buffer overflow capability was publicly ASSESSMENT: announced. ______________________________________________________________________________ Background CIAC received notice that a possible buffer overflow condition existed in pcAnywhere, version 9.0, via use of a public script. CIAC tested the script and found that a communications lockup was created by use of the script. CIAC notified Symantec of the finding and how CIAC created the condition. The notice also mentioned that this vulnerability is being examined to see if it can be exploited remotely to run user programs on a system. CIAC wishes to thank Symantec for its excellent response & communications in resolving this security issue. [****** Begin Symantec Security Alert ******] SARC Security Alert DTD: 05 March, 2001 Subject: pcAnywhere Denial of Service, abnormal server connection Affected: pcAnywhere v9.2x and v10.0 Problem: A Denial of Service condition exists in the Symantec pcAnywhere remote control solution that can result in the pcAnywhere server becoming unable to accept remote connections. Details: When the socket upon which the pcAnywhere server is listening is fed an abnormal amount of random characters immediately upon connection, any further communications between any pcAnywhere client and the server is prevented. The server indicates continuing to listen for a connection but no longer accepts client connections until the server application is restarted. Risk Impact: Low Risk, prevents remote administration of affected host until pcAnywhere server application is restarted. Solution: Symantec has developed fixes for pcAnywhere v 9.x and 10.x for this issue. Patches have been posted to the following location for download and are to be included in the pcAnywhere LiveUpdate the week of 5-9 March: pcA 9.x http://www.symantec.com/techsupp/files/pca/pca9-9598nt.html pcA 10.x http://www.symantec.com/techsupp/files/pca/pca_10.html Alert Location: This Security Alert can be viewed at http://service1.symantec.com/sarc/sarc.nsf/info/html/pcAnywhere.Denial.of.Servic e.html Credit: Symantec wishes to thank the engineers at the Computer Incident Advisory Capability (CIAC), Lawrence Livermore National Labs for their excellent coordination in helping resolve this issue. Copyright (c) 2001 by Symantec Corp. Permission to redistribute this Bulletin electronically is granted as long as it is not edited in any way unless authorized by the SARC. Reprinting the whole or part of this Bulletin in medium other than electronically requires permission from Sym Security@symantec.com. Disclaimer: The information in the advisory is believed to be accurate at the time of printing 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. Symantec, SARC and Sym Security are Registered Trademarks of Symantec Corp. and/or affiliated companies in the United States and other countries. All other registered and unregistered trademarks represented in this document are the sole property of their respective companies/owners. [****** End Symantec Security Alert ******] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of Symantec Corp. 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/ (or http://ciac.llnl.gov -- they're the same machine) Anonymous FTP: ftp.ciac.org (or ciac.llnl.gov -- they're the same machine) 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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