_____________________________________________________ The Computer Incident Advisory Capability ___ __ __ _ ___ / | / \ / \___ __|__ /___\ \___ _____________________________________________________ Information Bulletin March 28, 1991, 1200 PST Number B-21 Patch Available for SunOS 4.0.3 in.telnetd and in.rlogind ________________________________________________________________________ PROBLEM: SunOS versions 4.0.3 in.telnetd and in.rlogind may send output to an unauthorized user. PLATFORM: All Sun3 and Sun4 computers running SunOS 4.0.3. DAMAGE: May allow unauthorized access to the system. SOLUTIONS: Patch/update available from Sun as patch file 100125-03.tar.Z IMPACT OF PATCH: Vulnerability eliminated. No other side-effects reported. Critical Information about in.telnetd and in.rlogind Patch ________________________________________________________________________ Critical Information about in.telnetd and in.rlogind Patch CIAC information bulletin B-20 describes a problem with in.telnetd on Sun 3 and Sun 4 computers. The current bulletin contains a correction to part of the information in the previous bulletin concerning the applicability and installation of a patch for Sun OS 4.0.3 systems. Bulletin B-21 also provides information on an additional patch for a similar problem with in.rlogind in Sun OS 4.0.3 systems. Sun OS 4.1 or 4.1.1 systems are subject to the problem with in.telnetd but not to the problem with in.rlogind. For these systems, in.telnetd should be patched using the procedures listed in bulletin B-20. The Sun Microsystems patch described in bulletin B-20 may not work on some SunOS 4.0.3 systems. This vendor has, therefore, created a fix for the in.telnetd and in.logind utilities to patch SunOS 4.0.3 systems. If not patched, these utilities may allow unauthorized access to systems. The patch is available from Sun Microsystems as the updated Patch ID# 100125-03 (this number is required to order this patch from the Sun Answer Center). This patch is also available via anonymous ftp at uunet.uu.net (IP# 192.48.96.2) in the file sun-dist/100125-03.tar.Z. This patch file does not contain installation instructions. We recommend the following installation procedures, which supersede the procedures listed in bulletin B-20 for Sun OS 4.0.3 systems: 1. Log in as root on the system to be repaired. 2. Disable the flawed version of in.telnetd and in.rlogind with the following commands: # mv /usr/etc/in.telnetd /usr/etc/in.telnetd.FCS # mv /usr/etc/in.rlogind /usr/etc/in.rlogind.FCS # chmod 600 /usr/etc/in.telnetd.FCS /usr/etc/in.rlogind.FCS 3. Obtain the patch file 100125-03.tar.Z (either from Sun or a trusted anonymous FTP site such as uunet.uu.net). 4. Uncompress the patch file: # uncompress 100125-03.tar.Z 5. Extract the patch file appropriate to your architecture (either sun3, sun3x, sun4, or sun4c -- contact your Sun representative if you do not know which architecture you have) and your operating system level (either 4.0.3 or 4.0.3c) # tar xf 100125-03.tar {architecture}/4.0.3/in.telnetd # tar xf 100125-03.tar {architecture}/4.0.3/in.rlogind where {architecture} is one of sun3, sun3x, sun4, or sun4c*. 6. Copy the patch file to the appropriate directory, and set the ownership and permissions of the utility: # cp {architecture}/4.0.3/in.telnetd /usr/etc/in.telnetd # cp {architecture}/4.0.3/in.rlogind /usr/etc/in.rlogind # chown root.staff /usr/etc/in.telnetd /usr/etc/in.rlogind # chmod 711 /usr/etc/in.telnetd /usr/etc/in.rlogind 7. Kill any existing telnet and rlogin processes that may be running. # ps gax | grep in.telnetd # ps gax | grep in.rlogind # kill -9 #### where #### is the number of each in.telnetd process found in the previous ps commands. Please note that this command may disrupt ongoing sessions of users attempting to use the system. As an alternative to this step, you may consider rebooting the computer, allowing time for all current users to log out. Once you have verified that the new version of telnet is operational, it is advisable to delete the unpatched version of the utilities /usr/etc/in.telnetd.FCS and /usr/etc/in.rlogind.FCS to prevent their unauthorized use. For additional information or assistance, please contact CIAC: Tom Longstaff (415) 423-4416 or (FTS) 543-4416 During working hours call CIAC at (415) 422-8193 or (FTS) 532-8193 or send e-mail to ciac@cheetah.llnl.gov. Send FAX messages to: (415) 423-0913 or (FTS) 543-0913. _____ * - Note that for Sun4c systems, the correct file is sun4c/4.0.3c/in.telnetd and sun4c/4/0/3c/in.rlogind CERT/CC provided some of the information used in this bulletin. 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.