===================================================================== CERT-Renater Note d'Information No. 2006/VULN543 _____________________________________________________________________ DATE : 06/12/2006 HARDWARE PLATFORM(S) : / OPERATING SYSTEM(S) : Solaris 10 running Net-SNMP. ====================================================================== Sun(sm) Alert Notification * Sun Alert ID: 102725 * Synopsis: A Malformed Packet Received by snmpd(1) via TCP may Cause a Denial of Service (DoS) * Category: Security * Product: Solaris 10 Operating System * BugIDs: 6473670 * Avoidance: Workaround * State: Workaround * Date Released: 22-Nov-2006 * Date Closed: * Date Modified: 30-Nov-2006 1. Impact A local or remote unprivileged user may be able to disable the snmpd(1M) daemon causing a Denial of Service (DoS) of the SNMP service. This issue is also referenced at the following URL: * http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2005-2177 2. Contributing Factors This issue can occur in the following releases: SPARC Platform * Solaris 10 x86 Platform * Solaris 10 Note 1: Solaris 8 and Solaris 9 do not ship with the Net-SNMP software and thus are not impacted by this issue. Note 2: The Net-SNMP software was not bundled with Solaris prior to Solaris 10. However, customers who have built and/or installed a vulnerable version of Net-SNMP on any version of Solaris are at risk. See the Net-SNMP web site to download the latest version of Net-SNMP which addresses these issues. Note 3: The Solaris 10 patches which address this vulnerability do not increment the version of Net-SNMP. The version of Net-SNMP supplied with the patches will still be reported as 5.0.9. This issue only affects systems which have the SUNWsmagt package installed. To determine if the SUNWsmagt package is installed on the system, the following command can be used: $ pkginfo -l SUNWsmagt PKGINST: SUNWsmagt NAME: System Management Agent files and libraries CATEGORY: system VERSION: 1.0,REV=2005.01.08.05.16 Note: Only Net-SNMP 5.0.9 and earlier listening on TCP:161 (as delivered by SUNWsmagt)is affected by this issue. To confirm the version of Net-SNMP installed on the system, the following command can be used: $ /usr/sfw/sbin/snmpd -v NET-SNMP version: 5.0.9 Web: http://www.net-snmp.org/ Email: net-snmp-coders@lists.sourceforge.net If the version reported is 5.0.9 or earlier, and the above patch is not installed when testing the version of snmpd(1M) that is shipped with Solaris, then the described issue may occur. Note: The Net-SNMP distribution of snmpd(1M) by default listens only for UDP requests. To confirm whether "/usr/sfw/sbin/snmpd" is listening on port 161 for TCP requests, one can telnet to port 161 on the system in question: $ telnet 161 Trying x.x.x.x... Connected to .. Escape character is '^]'. Connection to . closed by foreign host. If a connection can be made to port 161 then it is likely that the snmp(1M) daemon is listening for TCP requests. To further verify that it is not a service other than snmpd(1M): $ grep 161 /etc/services The above command should only return the following: snmpd 161/udp snmp # SMA snmp daemon and possibly: snmpd 161/tcp snmp # SMA snmp daemon Note: Even if TCP is not listed for snmpd(1M) in /etc/services, it is possible that snmpd(1M) has been passed arguments at startup causing it to listen for tcp. 3. Symptoms If the described issue occurs, high utilization of system resources by snmpd(1), as viewed by a utility such as prstat(1M) may occur. 4. Relief/Workaround To work around the described issue, disable snmpd(1M) from listening to TCP requests on port 161 (UDP is unaffected). To Disable snmpd from listing to TCP requests on port 161, pass the following argument to snmpd(1M) at startup: UDP:161 For example : /usr/sfw/sbin/snmpd UDP:161 To Verify snmpd(1M) is no longer listening for TCP requests on port 161: $ telnet 161 telnet: Unable to connect to remote host: Connection refused 5. Resolution A final resolution is pending completion. Change History 30-Nov-2006: * Updated url in the Impact section 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. 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