************************************************************************** Security Bulletin 9542 DISA Defense Communications System October 27, 1995 Published by: DISN Security Coordination Center (SCC@NIC.DDN.MIL) 1-(800) 365-3642 DEFENSE INFORMATION SYSTEM NETWORK SECURITY BULLETIN The DISN SECURITY BULLETIN is distributed by the DISN SCC (Security Coordination Center) under DISA contract as a means of communicating information on network and host security exposures, fixes, and concerns to security and management personnel at DISN facilities. Back issues may be obtained via FTP (or Kermit) from NIC.DDN.MIL [192.112.36.5] using login="anonymous" and password="guest". The bulletin pathname is scc/disn-security-yynn (where "yy" is the year the bulletin is issued and "nn" is a bulletin number, e.g. scc/disn-security-9531). ************************************************************************** + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + ! ! ! The following important advisory was issued by the Automated ! ! Systems Security Incident Support Team (ASSIST) and is being ! ! relayed unedited via the Defense Information Systems Agency's ! ! Security Coordination Center distribution system as a means ! ! of providing DISN subscribers with useful security information. ! ! ! + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + -----BEGIN PGP SIGNED MESSAGE----- <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Automated Systems Security Incident Support Team _____ ___ ___ _____ ___ _____ | / /\ / \ / \ | / \ | | / Integritas / \ \___ \___ | \___ | | < et /____\ \ \ | \ | | \ Celeritas / \ \___/ \___/ __|__ \___/ | |_____\ <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Bulletin 95-40 Release date: 26 October, 1995, 1:15 PM EDT (GMT -4) SUBJECT: Sun 4.1.X Loadmodule Vulnerability. SUMMARY: A problem exists in the loadmodule(8) program in SunOS 4.1.X. A patch has been released by Sun to correct this problem. BACKGROUND: The loadmodule(8) program is used by the xnews(1) window system server to load two dynamically loadable kernel drivers into the currently running system and to create special devices in the /dev directory to use those modules. These modules and special files are used to provide a SunView binary compatibility mode while running the X11/NeWS windowing system. Because of the way the loadmodule(8) program sanitizes its environment, unauthorized users can gain root access on the local machine. A script for this problem is publicly available and has been used to exploit this vulnerability. This problem is present in SunOS 4.1.X only. IMPACT: Local users can gain root privileges. RECOMMENDED SOLUTIONS: ASSIST recommends DoD elements take the actions cited in A and B below. A. Obtain and install the appropriate patches according to the instructions included with the patches. Patches are available through your local Sun Answer Center and by FTP from ftp://sunsolve1.sun.com/pub/patches/100448-03.tar.Z Module Patch ID Filename ---------- --------- --------------- loadmodule 100448-03 100448-03.tar.Z Checksum: MD5 (100448-03.tar.Z) = 183a22f0a2f6020f1389b6aeea5ca6c6 B. Because, in general, a set-user-id program can lead to security exposures, you should also do at least step 1 below, and 2 and 3 are recommended as well. The intent of these directions is make the loadmodule(8) program work only for the super-user (currently it works for all users because it is set-user-id) and to execute it each time the system boots. By following these directions, users who require SunView binary compatibility will have it available to them. 1. If you do not need SunView binary compatibility, then as root, turn off setuid root on the loadmodule(8) program by executing the following command: # /bin/chmod u-s /usr/openwin/bin/loadmodule 2. If your users need SunView binary compatibility, you can enable it immediately--that is without having to reboot your system--with the following script. - ------------------------cut here--8<------------------------ ARCH=`/bin/arch -k` OBJ=/sys/${ARCH}/OBJ LM=/usr/openwin/bin/loadmodule /bin/chmod u-s $LM if [ -f $OBJ/evqmod-${ARCH}.o ]; then if /usr/etc/modstat | /bin/egrep -s evqmod ; then echo evq: already loaded elif $LM evqmod-${ARCH}.o evqload; then echo evq: loaded else echo evq: unable to load module fi fi if [ -f $OBJ/winlock-${ARCH}.o ]; then if /usr/etc/modstat | /bin/egrep -s winlock ; then echo winlock: already loaded elif $LM winlock-${ARCH}.o winlockload; then echo winlock: loaded else echo winlock: unable to load module fi fi - ------------------------cut here--8<------------------------ As a suggestion, store this script in /tmp/esbc and then execute it as root with: # sh /tmp/esbc 3. If you've done step 2 above, the module loadings will disappear the next time you reboot your system. To make them permanent-- that is to make these module loadings occur each time your system is rebooted--add the script to the end of your /etc/rc.local file. <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ASSIST would like to thank the CERT Coordination Center for information contained in this bulletin. <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ASSIST is an element of the Defense Information Systems Agency (DISA), Center for Information Systems Security (CISS), that provides service to the entire DoD community. Constituents of the DoD with questions about ASSIST or computer security issues, can contact ASSIST using one of the methods listed below. Non-DoD organizations/ institutions, contact the Forum of Incident Response and Security Teams (FIRST) representative. To obtain a list of FIRST member organizations and their constituencies send an email to docserver@first.org with an empty "subject" line and a message body containing the line "send first-contacts". ASSIST Information Resources: To be included in the distribution list for the ASSIST bulletins, send your Milnet (Internet) e-mail address to assist-request@assist.mil. Back issues of ASSIST bulletins, and other security related information, are available from the ASSIST BBS at 703-607-4710, 327-4710, and through anonymous FTP from assist.mil (IP address 199.211.123.11). Note: assist.mil will only accept anonymous FTP connections from Milnet addresses that are registered with the NIC or DNS. If your system is not registered, you must provide your MILNET IP address to ASSIST before access can be provided. ASSIST Contact Information: PHONE: 800-357-4231, COMM 703-607-4700, DSN 327-4700. ELECTRONIC MAIL: assist@assist.mil. ASSIST BBS: COMM 703-607-4710, DSN 327-4710, leave a message for the "sysop". FAX: COMM 703-607-4735, DSN 607-4735 ASSIST uses Pretty Good Privacy (PGP) 2.6.2 as the digital signature mechanism for bulletins. PGP 2.6.2 incorporates the RSAREF(tm) Cryptographic Toolkit under license from RSA Data Security, Inc. A copy of that license is available via anonymous FTP from net-dist.mit.edu (IP 18.72.0.3) in the file /pub/PGP/rsalicen.txt, and through the world wide web from http://net-dist.mit.edu/pgp.html. In accordance with the terms of that license, PGP 2.6.2 may be used for non-commercial purposes only. Instructions for downloading the PGP 2.6.2 software can also be obtained from net-dist.mit.edu in the pub/PGP/README file. PGP 2.6.2 and RSAREF may be subject to the export control laws of the United States of America as implemented by the United States Department of State Office of Defense Trade Controls. The PGP signature information will be attached to the end of ASSIST bulletins. Reference herein to any specific commercial product, process, or service by trade name, trademark manufacturer, or otherwise, does not constitute or imply its endorsement, recommendation, or favoring by ASSIST. The views and opinions of authors expressed herein shall not be used for advertising or product endorsement purposes. - -----BEGIN PGP PUBLIC KEY BLOCK----- Version: 2.6 mQCNAi4uZ40AAAEEAM1uraimCNeh5PtzX7KoGxC2u8uMTdl8V5sujk3MHbWvCuOM W0FqDy5s9iwfQLZWzJ7cbM6L0mNOj8eJGoz7TqGKZDDRFlKAwg0x8joleZLC2gXw FVdF/g6Mdv7ok7heoa+Y//YMeADnsSrmzqLCnhFbKYffww3EbdH6sbnW3Io9AAUR tB9BU1NJU1QgVGVhbSA8YXNzaXN0QGFzc2lzdC5taWw+iQCVAwUQL1xx7tH6sbnW 3Io9AQEBYwP9FvIJbnKjtMLUj8ghd6hophSx8WZnfQsOmZX/BbX8vKz1a5BkBn4q ANvW+uKGdUlE8LLMEm1PD59Cihcb3OoWDOU8zIOIErvry4eqa+LzEXV8nnBdes+A a1MCMGSz+K3OaP78lQ7JCGoY9TXTWIelfAdBVBG4VQcSQRn8tjRdG2e0KEFTU0lT VCBUZWFtIDxhc3Npc3RAYXNzaXN0Lmltcy5kaXNhLm1pbD6JAJUCBRAuLnHoh0Y9 0jC+b6kBAU0TA/4yXSL7K6tcfVm9ACnP4crCoutFM2w10e7YKxD850ajhWrh6rI9 O+sjU5WObqiPJ7sZHdEw/KARzPSijH/5h8HlyYa6ClksWxYuymzCsUYYJctdjcGr uakfXgYQ1TkkyUfNrN5G90NuRK/vTRe7bkmyGNYjN9Njac1Q18WVF59Chg== =d5rP - -----END PGP PUBLIC KEY BLOCK----- -----BEGIN PGP SIGNATURE----- Version: 2.6 iQCVAwUBMI/CsNH6sbnW3Io9AQHJrgP+OKuuKEtiYUZ96dtKo6Mv7uohpujvfmOT 5K62zlC74A2lbm2XMoHP96GOID2vcD8K2ZD6FWf8RpU7j//MErDebfDFsmt4pS6D 6sIFQESe77brwPVfEO0VTrhfKzz1sw0jQX2tWcXPjqeBQucjAIqAngesykoCTAeD qHDHgUhJE8U= =yXei -----END PGP SIGNATURE----- **************************************************************************** * * * The point of contact for NIPRNET security-related incidents is the * * Security Coordination Center (SCC). * * * * E-mail address: SCC@NIC.DDN.MIL * * * * Telephone: 1-(800)-365-3642 * * * * NIC Help Desk personnel are available from 7:00 a.m.-7:00 p.m. EST, * * Monday through Friday except on federal holidays. * * * **************************************************************************** PLEASE NOTE: Some users outside of the DOD computing communities may receive DISN Security Bulletins. If you are not part of the DOD community, please contact your agency's incident response team to report incidents. Your agency's team will coordinate with DOD. 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 by sending email to docserver@first.org with an empty subject line and a message body containing the line: send first-contacts. This document was prepared as an service to the DOD community. Neither the United States Government nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, 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. The opinions of the authors expressed herein do not necessarily state or reflect those of the United States Government, and shall not be used for advertising or product endorsement purposes.