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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2005.0356 -- Sun Alert Notification 57746 Sun TCP Connections May Experience Performance Degradation If Certain ICMP Error Messages Are Received 3 May 2005 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Solaris Publisher: Sun Microsystems Operating System: Solaris 10 Solaris 9 Solaris 8 Solaris 7 Impact: Denial of Service Access: Remote/Unauthenticated CVE Names: CAN-2004-0791 CAN-2004-0790 Original Bulletin: http://sunsolve.sun.com/search/printfriendly.do?assetkey=1-26-57746-1 - --------------------------BEGIN INCLUDED TEXT-------------------- Sun(sm) Alert Notification * Sun Alert ID: 57746 * Synopsis: Sun TCP Connections May Experience Performance Degradation If Certain ICMP Error Messages Are Received * Category: Security * Product: Solaris * BugIDs: 5084452 * Avoidance: None * State: Committed * Date Released: 12-Apr-2005 * Date Closed: * Date Modified: 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 [1]http://www.ietf.org/internet-drafts/draft-gont-tcpm-icmp-attacks-03.txt CERT Vulnerability Note VU#222750 at [2]http://www.kb.cert.org/vuls/222750 CVEs CAN-2004-0790 at [3]http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2004-0790 CVEs CAN-2004-0791 at [4]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 * Solaris 9 * Solaris 10 x86 Platform * Solaris 7 * Solaris 8 * Solaris 9 * Solaris 10 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 <output-file> 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 4. Relief/Workaround There is no workaround for this issue at this time. 5. Resolution A final resolution is pending completion. 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 2000-2005 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, CA 95054 U.S.A. All rights reserved. References 1. http://www.ietf.org/internet-drafts/draft-gont-tcpm-icmp-attacks-03.txt 2. http://www.kb.cert.org/vuls/222750 3. http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2004-0790 4. http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2004-0791 - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/render.html?cid=1980 If you believe that your computer system has been compromised or attacked in any way, we encourage you to let us know by completing the secure National IT Incident Reporting Form at: http://www.auscert.org.au/render.html?it=3192 =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQCVAwUBQnbaUCh9+71yA2DNAQJpIQP/aW3eOf9w+1JQ//cZHGn9qU4SgWGihX60 PwSFZQ4JFvylDVJmiDbhPCqby9valmIlzoArB8IhavfbIH0cx6DLpsqAp6FICEHr EKSVAqP+71d+tpH/hUKjiR0qAmoPRyb3TE83Z8l2mkSZtcItVQsMRdtNFV6dEN1/ xuJDFweocn8= =MLUV -----END PGP SIGNATURE-----