__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Security Vulnerability in the in.telnetd(1M) Daemon [Sun Alert ID: 102802] February 14, 2007 16:00 GMT Number R-139 ______________________________________________________________________________ PROBLEM: A security vulnerability in the in.telnetd(1M) daemon shipped with Solaris 10. PLATFORM: SPARC Platform Solaris 10 without patch 120068-02 x86 Platform Solaris 10 without patch 120069-02 DAMAGE: May allow a local or remote unprivileged user who is able to connect to a host using the telnet(1) service to gain unauthorized access to that host by connecting as any user on the system, allowing them to execute arbitrary commands with the privileges of that user. SOLUTION: Upgrade to the appropriate version. ______________________________________________________________________________ VULNERABILITY The risk is MEDIUM. A remote unprivileged user who can login to ASSESSMENT: a system using telnet can get root access. ______________________________________________________________________________ LINKS: CIAC BULLETIN: http://www.ciac.org/ciac/bulletins/r-139.shtml ORIGINAL BULLETIN: http://www.sunsolve.sun.com/search/document.do?assetkey=1 -26-102802-1 CVE: http://www.cve.mitre.org/cgi-bin/cvename.cgi?name= CVE-2007-0882 ______________________________________________________________________________ REVISION HISTORY: 02/22/2007 - revised R-139 to reflect changes Sun has made in Sun Alert ID: 102802 where they Updated the Resolution section. [***** Start Sun Alert ID: 102802 *****] Sun(sm) Alert Notification Sun Alert ID: 102802 Synopsis: Security Vulnerability in the in.telnetd(1M) Daemon May Allow Unauthorized Remote Users to Gain Access to a Solaris Host Category: Security Product: Solaris 10 Operating System BugIDs: 6523815 Avoidance: Patch, Workaround State: Resolved Date Released: 12-Feb-2007, 13-Feb-2007 Date Closed: 13-Feb-2007 Date Modified: 13-Feb-2007, 14-Feb-2007, 16-Feb-2007 1. Impact A security vulnerability in the in.telnetd(1M) daemon shipped with Solaris 10 may allow a local or remote unprivileged user who is able to connect to a host using the telnet(1) service to gain unauthorized access to that host by connecting as any user on the system, allowing them to execute arbitrary commands with the privileges of that user. This would include the root user (uid 0) if the host is configured to accept telnet logins as the root user. This issue is described in the following documents: CERT VU#881872 at http://www.kb.cert.org/vuls/id/881872 CVE-2007-0882 at http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-0882 2. Contributing Factors This issue can occur in the following releases: SPARC Platform * Solaris 10 without patch 120068-02 x86 Platform * Solaris 10 without patch 120069-02 Notes: Solaris 8 and 9 are not affected by this issue. This issue only affects systems which have the telnet(1) service enabled. The following command can be used to determine if the service is enabled, which will output 'online' for the service state if the system is affected by this issue: $ svcs telnet STATE STIME FMRI online Jan_30 svc:/network/telnet:default If remote root logins are disabled, the impact of this issue will be limited to users other than root. Remote root logins are disabled if the file "/etc/default/login" contains a line that begins with 'CONSOLE'. This can be seen using the grep command as shown below: $ grep CONSOLE /etc/default/login CONSOLE=/dev/console If this line has been commented out by inserting a '#' at the beginning, as in the following example: #CONSOLE=/dev/console or if there is no line containing the word 'CONSOLE', then this issue will also apply to the root user. See login(1) for more information about the /etc/default/login file. 3. Symptoms Depending on the manner in which this issue has been exploited, the output from commands such as last(1) (which display information about login and logout activity), may show unexpected logins to the system. Using the '-a' flag with the last(1) command will show the hostname associated with these logins. Solution Summary Top 4. Relief/Workaround To workaround this issue, the telnet service can be disabled as in the following example (Note that this will remove the functionality of the in.telnetd daemon on that host): # svcadm disable svc:/network/telnet:default Note: If instead of disabling the service, removal of the service is being considered, then please first read Sun Alert 102799: "Synopsis: svc.startd(1M) May Core Dump While Removing a Service, Causing patchrm(1M) to Terminate and Leave the System Unbootable" In addition, it is also possible to uncomment (or add) the 'CONSOLE' line in the "/etc/default/login" file so that it looks similar to the following: CONSOLE=/dev/console However, this will only prevent unauthorized access to the root account; other user accounts will still be affected by this issue. 5. Resolution This issue is addressed in the following releases: SPARC Platform * Solaris 10 with patch 120068-02 or later x86 Platform * Solaris 10 with patch 120069-02 or later Note: These patches have been created with a tag that says that a reboot is required after installation. However, this is incorrect (see Bug 6524404). Future Solaris 10 telnetd(1M) patch revisions have had this tag removed. Change History 13-Feb-2007: Updated Contributing Factors and Resolution sections State: Resolved 14-Feb-2007: Updated Relief/Workaround section 16-Feb-2007: Updated Resolution 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. All rights reserved. [***** End Sun Alert ID: 102802 *****] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of Sun Microsystems 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. 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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