===================================================================== CERT-Renater Note d'Information No. 2006/VULN181 _____________________________________________________________________ DATE : 21/04/2006 HARDWARE PLATFORM(S) : Sun OPERATING SYSTEM(S) : Sun Siloaris ====================================================================== Sun(sm) Alert Notification * Sun Alert ID: 101658 (formerly 57746) * Synopsis: Sun TCP Connections May Experience Performance Degradation If Certain ICMP Error Messages Are Received * Category: Security * Product: Solaris 9 Operating System, Solaris 10 Operating System, Solaris 7 Operating System, Solaris 8 Operating System * BugIDs: 5084452 * Avoidance: Patch * State: Workaround * Date Released: 12-Apr-2005 * Date Closed: * Date Modified: 07-Jun-2005, 02-Feb-2006, 03-Mar-2006, 21-Mar-2006, 12-Apr-2006 1. Impact This Sun Alert describes the Sun specific impact of the issues described in the Internet-Draft (I-D) titled "ICMP attacks against TCP" written by Fernando Gont. The I-D describes how TCP(7P) connections could be reset and disconnected as a result of ICMP(7P) error messages. Solaris will not drop established TCP connections based on ICMP errors. There is a theoretical possibility that a TCP connection which is in the process of being set up could be terminated before being established. However, there is no risk of data corruption or compromise in this scenario. The draft also describes ICMP messages which could impact the performance of existing TCP connections. This issue affects all current versions of Solaris and thus Sun plans on improving how ICMP errors are handled to further mitigate the impact of such ICMP messages. This issue is also described in the following documents: IETF Internet Draft at http://www.ietf.org/internet-drafts/draft-gont-tcpm-icmp-attacks-03.txt CERT Vulnerability Note VU#222750 at http://www.kb.cert.org/vuls/id/222750 CVEs CAN-2004-0790 at http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2004-0790 CVEs CAN-2004-0791 at http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2004-0791 2. Contributing Factors This issue can occur in the following releases: SPARC Platform * Solaris 7 * Solaris 8 without patch 116965-19 * Solaris 9 without patch 118305-08 * Solaris 10 without patch 118822-27 x86 Platform * Solaris 7 * Solaris 8 without patch 116966-18 * Solaris 9 without patch 117470-07 * Solaris 10 without patch 118844-28 3. Symptoms In order to verify if ICMP error messages are being sent to a specific system on the network, a network monitoring tool such as snoop(1M) can be used from either the specific system or another system on the same network. The following command can be run (as "root"): # snoop -o Afterwards, the snoop(1M) utility can display the packets captured in the "output-file" using the "-v" and "-i" options, as in: # snoop -v -i output-file icmp icmp6 and inspect the output for ICMP packets which will look similar to the following: ICMP: ----- ICMP Header ----- ICMP: ICMP: Type = 0 (Echo reply) ICMP: Code = 0 (ID: 5417 Sequence number: 0) ICMP: Checksum = be96 ICMP: If the "Type" value and the "Code" value (for multiple packets) are equal to any of the following combinations: Type Code Name ---- ---- ----------------- 4 0 Source Quench 3 * Net/Host/Protocol/Port Unreachable, etc. 5 * Redirect 6 0 Alternate Host Address 11 * Time Exceeded 12 * Parameter Problem then the system may be the target of the described ICMP issue. Solution Summary Top 4. Relief/Workaround There is no workaround for this issue. Please see the Resolution section below. 5. Resolution This issue is addressed in the following releases: SPARC Platform * Solaris 8 with patch 116965-19 or later * Solaris 9 with patch 118305-08 or later * Solaris 10 with patch 118822-27 or later x86 Platform * Solaris 8 with patch 116966-18 or later * Solaris 9 with patch 117470-07 or later * Solaris 10 with patch 118844-28 or later A final resolution is pending completion for Solaris 7. Change History 07-Jun-2005: * Correction to CERT URL made in Impact section 02-Feb-2006: * Updated Contributing Factors and Resolution sections 03-Mar-2006: * Updated Contributing Factors and Resolution sections 21-Mar-2006: * Updated Contributing Factors and Resolution sections 12-Apr-2006: * 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, the Sun.com Terms of Use. This Sun Alert notification may only be used for the purposes contemplated by these agreements. Copyright 2000-2006 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, CA 95054 U.S.A. All rights reserved. ====================================================================== ========================================================= Les serveurs de référence du CERT-Renater http://www.urec.fr/securite http://www.cru.fr/securite http://www.renater.fr ========================================================= + CERT-RENATER | tel : 01-53-94-20-44 + + 151 bd de l'Hopital | fax : 01-53-94-20-41 + + 75013 Paris | email: certsvp@renater.fr + =========================================================