Published:
28 April 1998
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-----BEGIN PGP SIGNED MESSAGE----- =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-98.062 -- CERT VB-98.04 Vulnerabilities in Xterm and Xaw 29 April 1998 =========================================================================== CERT/CC has released the following advisory concerning vulnerabilities in the terminal emulator xterm(1), and the Xaw library distributed in various MIT X Consortium; X Consortium, Inc.; and The Open Group X Project Team releases. These vulnerabilities may be exploited by an intruder to gain root access. The following security bulletin is provided as a service to AUSCERT's members. As AUSCERT did not write this document, AUSCERT has had no control over its content. As such, the decision to use any or all of this information is the responsibility of each user or organisation, and should be done so in accordance with site policies and procedures. NOTE: This is only the original release of the security bulletin. It will not be updated when the original bulletin is. If downloading at a later date, it is recommended that the bulletin is retrieved from the original authors to ensure that the information is still current. Contact information for CERT/CC and The Open Group is included in the Security Bulletin below. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/Information/advisories.html If you believe that your system has been compromised, contact AUSCERT or your representative in FIRST (Forum of Incident Response and Security Teams). Internet Email: auscert@auscert.org.au Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AUSCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for emergencies. Facsimile: (07) 3365 7031 - ---------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- ============================================================================= CERT* Vendor-Initiated Bulletin VB-98.04 April 27, 1998 Topic: Vulnerabilities in xterm and Xaw Source: The Open Group To aid in the wide distribution of essential security information, the CERT Coordination Center is forwarding the following information from The Open Group. The Open Group urges you to act on this information as soon as possible. Further questions about these vulnerabilities should be directed to your vendor or support personnel. =======================FORWARDED TEXT STARTS HERE============================ ______________________________________________________________________________ The Open Group X Project Team Security Advisory Title: xterm and Xaw library vulnerability Date: April 27, 1998 ______________________________________________________________________________ The Open Group X Project Team provides this information freely to the X11 user community for its consideration, interpretation, implementation and use. The Open Group X Project Team recommends that this information be acted upon as soon as possible. The Open Group X Project Team provides the information in this Security Advisory on an "AS-IS" basis only, and disclaims all warranties with respect thereto, express, implied or otherwise, including, without limitation, any warranty of merchantability or fitness for a particular purpose. In no event shall The Open Group be liable for any loss of profits, loss of business, loss of data or for any indirect, special, exemplary, incidental or consequential damages of any kind arising from your use of, failure to use or improper use of any of the instructions or information in this Security Advisory. ______________________________________________________________________________ I. Description Vulnerabilities exist in the terminal emulator xterm(1), and the Xaw library distributed in various MIT X Consortium; X Consortium, Inc.; and The Open Group X Project Team releases. These vulnerabilities may be exploited by an intruder to gain root access. The resources and the releases affected by the xterm vulnerability are: Resources inputMethod preeditType *Keymap Release X11R3 NO NO YES X11R4 NO NO YES X11R5 NO NO YES X11R6 NO NO YES X11R6.1 YES YES YES X11R6.2 YES YES YES X11R6.3 YES YES YES X11R6.4 YES YES YES The resources and the releases affected by the Xaw library vulnerability are Resources inputMethod preeditType Release X11R6 YES YES X11R6.1 YES YES X11R6.2 YES YES X11R6.3 YES YES X11R6.4 YES YES (X11R6.2 was not released to the public.) The Open Group X Project Team has investigated the issue and recommends the following steps for neutralizing the exposure. It is HIGHLY RECOMMENDED that these measures be implemented on ALL vulnerable systems. This issue will be corrected in future X Project Team releases of X11. - - - - -------------- - - - - --- Impact --- - - - - -------------- By crafting an arbitrarily long string that contains embedded machine code and using it to set specific "resources", a user may obtain a shell prompt that has root privileges. Anyone using the MIT X Consortium; X Consortium, Inc.; or X Project Team xterm and that has xterm installed setuid-root may be vulnerable. Anyone using an xterm based on any of the sources listed above may also be vulnerable to the xterm vulnerability. In order to be vulnerable to the Xaw library vulnerability, the Xaw Text widget must be used by a setuid-root program. Anyone using an Xaw replacement based on any of the released versions of Xaw listed above (e.g. Xaw3d) may also be vulnerable to the Xaw vulnerability. - - - - -------------------------- - - - - --- Temporary Solution --- - - - - -------------------------- 1) Become the root user on the system. % /bin/su - Password: # 2) Remove the setuid-root bit from the xterm binary. # chmod 0755 <path-to-xterm>/xterm For the Xaw vulnerability, remove the suid-root bit from any programs which use the Xaw text widget. 2) Remove the setuid-root bit from the binary. # chmod 0755 <setuid-root-program> - - - - ---------------- - - - - --- Solution --- - - - - ---------------- Patches to address this vulnerability have been given to X Project Team members: Astec Attachmate BARCO Chromatics CliniComp International Digital Hewlett-Packard Hitachi Hummingbird Communications IBM Jupiter Systems Metro Link Network Computing Devices NetManage Peritek Seaweed Systems Sequent Computer Systems Shiman Associates Silicon Graphics Societe Axel Siemens Nixdorf Starnet SunSoft WRQ Xi Graphics The X Project Team periodically makes public patches available to fix a variety of problems. Announcements about the availability of these patches is announced on the Usenet comp.windows.x.announce newsgroup. The patches, when they become available, may be found on ftp://ftp.x.org/pub/R6.4/fixes/. The X Project Team only supplies patches for the latest release -- we do not make patches for prior releases. Information on joining The Open Group can be found at http://www.opengroup.org/howtojoin.htm ========================FORWARDED TEXT ENDS HERE============================= If you believe that your system has been compromised, contact the CERT Coordination Center or your representative in the Forum of Incident Response and Security Teams (FIRST). See http://www.first.org/team-info/. We strongly urge you to encrypt any sensitive information you send by email. The CERT Coordination Center can support a shared DES key and PGP. Contact the CERT staff for more information. Location of CERT PGP key ftp://ftp.cert.org/pub/CERT_PGP.key CERT Contact Information - - ------------------------ Email cert@cert.org Phone +1 412-268-7090 (24-hour hotline) CERT personnel answer 8:30-5:00 p.m. EST (GMT-5)/EDT(GMT-4), and are on call for emergencies during other hours. Fax +1 412-268-6989 Postal address CERT Coordination Center Software Engineering Institute Carnegie Mellon University Pittsburgh PA 15213-3890 USA CERT publications, information about FIRST representatives, and other security-related information are available from http://www.cert.org/ ftp://ftp.cert.org/pub/ CERT advisories and bulletins are also posted on the USENET newsgroup comp.security.announce To be added to our mailing list for CERT advisories and bulletins, send your email address to cert-advisory-request@cert.org In the subject line, type SUBSCRIBE your-email-address * Registered U.S. Patent and Trademark Office. The CERT Coordination Center is part of the Software Engineering Institute (SEI). The SEI is sponsored by the U. S. Department of Defense. This file: ftp://ftp.cert.org/pub/cert_bulletins/VB-98.04.xterm.Xaw - -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBNUTuuXVP+x0t4w7BAQEbnwQA3DJTOrIvrnizEvHb2RojMNm/Hmu5dqHL ber6ArkrMaqITjJpgLnoGKy3n9x4DOWt/4008gm9g11rRpHoOEPPDha5oSi+vpqh MMkh7ALe8J1OiHmzUy0MJA4xBblGbimEsI0pTZgsP6ndHhZXAJX1Kd6BuL+Pp+PX oqHgg+9cBLQ= =KOjp - -----END PGP SIGNATURE----- - --------------------------END INCLUDED TEXT---------------------- -----BEGIN PGP SIGNATURE----- Version: 2.6.3i Charset: noconv Comment: ftp://ftp.auscert.org.au/pub/auscert/AUSCERT_PGP.key iQCVAwUBNU7WpCh9+71yA2DNAQHYIwP5AQpwWCXpF0KJUXSy0c37e8XlHXJSNfax z6kv+M/firHB9Z1SaVT6NDOADWoR51aa37u8FLQ6iPfoIpWOliMExEqKi64HxYB3 yYppW7cxQvyFRCihUmhF+S/v8Qpyw1XRR63vAUQsVH319SdC/m10PxC/fZ/c8YrC 3cNLUCxxy+Q= =8Qws -----END PGP SIGNATURE-----