===================================================================== CERT-Renater Note d'Information No. 2007/VULN052 _____________________________________________________________________ DATE : 15/02/2007 HARDWARE PLATFORM(S) : / OPERATING SYSTEM(S) : Solaris 10 running telnet. ====================================================================== 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 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: 1. Solaris 8 and 9 are not affected by this issue. 2. 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. 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 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 Change History 13-Feb-2007: * Updated Contributing Factors and Resolution sections * State: Resolved 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. 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