__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN HP-UX ICMP Vulnerable to DoS via ICMP Path [US-CERT Vulnerability Note VU#972686] April 13, 2007 17:00 GMT Number R-209 [REVISED 11 May 2007] ______________________________________________________________________________ PROBLEM: A vulnerability in HP-UX may allow a remote attacker to cause a denial of service by sending a specially crafted ICMP packet. PLATFORM: HP-UX 11 DAMAGE: A remote unauthenticated attacker may be able to cause a denial of service by sending a specially crafted ICMP packet to any open TCP/IP connection. SOLUTION: Upgrade the appropriate patch. ______________________________________________________________________________ VULNERABILITY The risk is LOW. A remote unauthenticated attacker may be able ASSESSMENT: to cause a denial of service by sending a specially crafted ICMP packet to any open TCP/IP connection. ______________________________________________________________________________ LINKS: CIAC BULLETIN: http://www.ciac.org/ciac/bulletins/r-209.shtml ORIGINAL BULLETIN: http://www.kb.cert.org/vuls/id/972686 ADDITIONAL LINK: Visit Hewlett-Packard's Subscription Service for: HPSBUX01137 SSRT5954 rev. 11 CVE: http://www.cve.mitre.org/cgi-bin/cvename.cgi?name= CVE-2005-1192 ______________________________________________________________________________ REVISION HISTORY: 05/11/2007 - revised R-209 to add a link to Hewlett-Packard HPSBUX01137 SSRT5954 rev. 10. [***** Start US-CERT Vulnerability Note VU#972686 *****] Vulnerability Note VU#972686 HP-UX ICMP vulnerable to DoS via ICMP Path Maximum Transmission Unit (PMTU) Discovery Overview A vulnerability in HP-UX may allow a remote attacker to cause a denial of service by sending a specially crafted ICMP packet. I. Description A number of widely accepted Internet standards describe different aspects of the relationships between the Internet Control Message Protocol (ICMP) and Transmission Control Protocol (TCP). In particular, RFC 1122 explains how TCP should respond to ICMP messages. Path MTU Discovery (RFC1191) is a method used to discover the maximum transmission unit (MTU) of an arbitrary internet path by using ICMP messages. HP-UX 11 contains an unspecified vulnerability in how it handles Path MTU Discovery messages. This may allow a remote attacker to cause a denial-of- service condition. II. Impact A remote unauthenticated attacker may be able to cause a denial of service by sending a specially crafted ICMP packet to any open TCP/IP connection. The denial of service can only be corrected by a reboot of the affected system. III. Solution Apply a patch Apply a patch, as specified in HP Technical Document c00571568. Set the PMTU Strategy Until patches are available, the denial of service may be avoided by setting the ip_pmtu_strategy parameter to 0 or 3, as specified in the HP Security Bulletin. Systems Affected Vendor Status Date Updated Hewlett-Packard Company Vulnerable 26-Apr-2005 References http://www2.itrc.hp.com/service/cki/docDisplay.do?docId=c00571568 http://www1.itrc.hp.com/service/cki/docDisplay.do?docId=HPSBUX01137 http://www.securitytracker.com/alerts/2005/Apr/1013798.html http://secunia.com/advisories/15123/ Credit Thanks to HP for reporting this vulnerability. This document was written by Will Dormann. Other Information Date Public 04/24/2005 Date First Published 04/12/2007 12:46:03 PM Date Last Updated 04/12/2007 CERT Advisory CVE Name CVE-2005-1192 Metric 4.05 Document Revision 10 [***** End US-CERT Vulnerability Note VU#972686 *****] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of US-CERT 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. 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