-----BEGIN PGP SIGNED MESSAGE----- ****************************************************************************** ------ ----- ----- --- ----- | ----- ---- | | | | | |--- | | | | | | | | | |-- | | | | |-- | | | | | | | | \ | | ----- ---- ----- ----- | \ ----- A D V I S O R Y 97.04 ****************************************************************************** Topic: Vulnerability in Natural Language Service Source: CERT/CC Creation Date: April 24, 1997 Last Updated: May 1, 1997 To aid in the wide distribution of essential security information, FedCIRC is forwarding the following information from . FedCIRC urges you to act on this information as soon as possible. If you have any questions, please contact FedCIRC: Telephone: +1 888 282 0870 Email: fedcirc@fedcirc.gov =======================FORWARDED TEXT STARTS HERE============================ ============================================================================= CERT* Advisory CA-97.10 Original issue date: April 24, 1997 Last revised: May 1, 1997 Section III and Appendex. Updated vendor information for Hewlett-Packard Company. Topic: Vulnerability in Natural Language Service - - ----------------------------------------------------------------------------- The CERT Coordination Center has received reports of a buffer overflow condition that affects some libraries using the Natural Language Service (NLS) on UNIX systems. By exploiting this vulnerability, any local user can execute arbitrary programs as a privileged user. There is a possibility (with some old libraries) that the vulnerability can be exploited by a remote user. Exploitation information is publicly available. The CERT/CC team recommends installing patches when they become available. We will update this advisory as we receive additional information. Please check advisory files regularly for updates that relate to your site. - - ----------------------------------------------------------------------------- I. Description A buffer overflow condition affects libraries using the Natural Language Service (NLS). The NLS is the component of UNIX systems that provides facilities for customizing the natural language formatting for the system. Examples of the types of characteristics that can be set are language, monetary symbols and delimiters, numeric delimiters, and time formats. Some libraries that use a particular environment variable associated with the NLS contain a vulnerability in which a buffer overflow condition can be triggered. The particular environment variable involved is NLSPATH on some systems and PATH_LOCALE on others. It is possible to exploit this vulnerability to attain unauthorized access by supplying carefully crafted arguments to programs that are owned by a privileged user-id and that have setuid or setgid bits set. Exploit information involving this vulnerability has been made publicly available. II. Impact Local users (users with access to an account on the system) are able to execute arbitrary programs as a privileged user without authorization. There is a possibility (with some old libraries) that the vulnerability can be exploited by a remote user. III. Solution Install a patch for this problem when one becomes available. Currently, there is no workaround to use in the meantime. Below is a list of vendors who have provided information about this problem. Details are in Appendix A of this advisory; we will update the appendix as we receive more information. If your vendor's name is not on this list, the CERT/CC did not hear from that vendor. Please contact your vendor directly. Berkeley Software Design, Inc. (BSDI) Cray Research - A Silicon Graphics Company Data General Corporation Digital Equipment Corporation Hewlett-Packard Company IBM Corporation Linux Systems NEC Corporation NeXT/Apple The Santa Cruz Operation (SCO) Solbourne Sun Microsystems, Inc. ........................................................................... Appendix A - Vendor Information Below is a list of the vendors who have provided information for this advisory. We will update this appendix as we receive additional information. If you do not see your vendor's name, the CERT/CC did not hear from that vendor. Please contact the vendor directly. Berkeley Software Design, Inc. (BSDI) ===================================== No versions of BSD/OS are vulnerable to this problem. Cray Research - A Silicon Graphics Company ========================================== We're investigating. Data General Corporation ======================== We're investigating. Digital Equipment Corporation ============================= SOURCE: Digital Equipment Corporation Software Security Response Team Copyright (c) Digital Equipment Corporation 1997. All rights reserved. This reported problem is not present for Digital's ULTRIX or Digital UNIX Operating Systems Software. Hewlett-Packard Company ======================= HP has completed their testing, HP-UX is not vulnerable. IBM Corporation =============== All AIX releases are vulnerable to a variation of this advisory. AIX 3.2.5 --------- Apply the following fix to your system: PTFs - U447656 U447671 U447676 U447682 U447705 U447723 (APAR IX67405) To determine if you have these PTFs on your system, run the following command: lslpp -lB U447656 U447671 U447676 U447682 U447705 U447723 AIX 4.1 ------- Apply the following fix to your system: APAR - IX67407 To determine if you have this APAR on your system, run the following command: instfix -ik IX67407 Or run the following command: lslpp -h bos.rte.libc Your version of bos.rte.libc should be 4.1.5.7 or later. AIX 4.2 ------- Apply the following fixes to your system: APAR - IX67377 IX65693 To determine if you have these APARs on your system, run the following command: instfix -ik IX67377 IX65693 Or run the following command: lslpp -h bos.rte.libc Your version of bos.rte.libc should be 4.2.0.11 or later. (APAR IX65693 fixes a problem with the mkgroup command after IX67377 is applied.) To Order -------- APARs may be ordered using Electronic Fix Distribution (via FixDist) or from the IBM Support Center. For more information on FixDist, reference URL: http://service.software.ibm.com/aixsupport/ or send e-mail to aixserv@austin.ibm.com with a subject of "FixDist". IBM and AIX are registered trademarks of International Business Machines Corporation. Linux Systems ============= Linux systems running older C libraries are vulnerable. To check which C library is being used type linux% ldd /bin/ls libc.so.5 => /lib/libc.so.5.3.12 This indicates the machine is using libc 5.3.12. C libraries older than 5.3.12 (that is libc5.2.18, libc5.0.9 etc) are vulnerable to this bug and you should upgrade the C library. The release versions of libc 5.4.x are immune to this attack. If you have libc5.3.12 it is insecure unless it is the modified libc5.3.12 shipped with Red Hat 4.1, or as an upgrade on Red Hat 4.0. You can check this with the package manager: linux# rpm -q libc libc-5.3.12-17 Indicates you have version 17 of the package. This is the safe one. Red Hat 4.0 users who have not already upgraded their libc can obtain this package at ftp://ftp.redhat.com/pub/redhat/old-releases/redhat-4.0/updates/. NEC Corporation =============== NEC platforms are not affected by this vulnerability. NeXT/Apple ========== No versions of NeXTstep of OpenStep/Mach are vulnerable to this problem. The Santa Cruz Operation (SCO) ============================= We are investigating this problem and will provide updated information for this advisory when it becomes available. Solbourne ========= Solbourne is not vulnerable. Sun Microsystems, Inc. ====================== Not vulnerable. - - ----------------------------------------------------------------------------- The CERT Coordination Center staff thanks Wolfgang Ley of DFN-CERT for his input to this advisory and Bruce Ide for drawing our attention to the problem. - - ----------------------------------------------------------------------------- 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 (see http://www.first.org/team-info). CERT/CC 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 Using encryption We strongly urge you to encrypt sensitive information sent by email. We can support a shared DES key or PGP. Contact the CERT/CC for more information. Location of CERT PGP key ftp://info.cert.org/pub/CERT_PGP.key Getting security information CERT publications and other security information are available from http://www.cert.org/ ftp://info.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 advisories and bulletins, send email to cert-advisory-request@cert.org In the subject line, type SUBSCRIBE your-email-address - - --------------------------------------------------------------------------- Copyright 1997 Carnegie Mellon University This material may be reproduced and distributed without permission provided it is used for noncommercial purposes and the copyright statement is included. * Registered U.S. Patent and Trademark Office. - - --------------------------------------------------------------------------- This file: ftp://info.cert.org/pub/cert_advisories/CA-97.10.nls http://www.cert.org click on "CERT Advisories" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Revision history May 1, 1997 Section III and Appendex. Updated vendor information for Hewlett-Packard Company. Acknowledgments - added a name upon receiving permission to do so. ========================FORWARDED TEXT ENDS HERE============================= The National Institute of Standards and Technology (NIST) has established a Federal Computer Incident response Capability (FedCIRC) to assist federal civilians agencies in their incident handling efforts by providing proactive and reactive computer security related services. FedCIRC is a partnership among NIST, the Computer Incident Advisory Capability (CIAC), and the CERT* Coordination Center (CERT/CC). If you believe that your system has been compromised, please contact FedCIRC: Telephone: +1 888 282 0870 Email: fedcirc@fedcirc.gov Web Server: http://www.fedcirc.gov/ * Registered in U.S. Patent and Trademark Office The CERT Coordination Center is part of the Software Engineering Institute. The Software Engineering Institute is sponsored by the U.S. Department of Defense. 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. 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. -----BEGIN PGP SIGNATURE----- Version: 2.6.2 Comment: Processed by Mailcrypt 3.3, an Emacs/PGP interface iQCVAwUBM5bchHVP+x0t4w7BAQHYRAQAw3wi7iJ12W/t5QXyLV8dpNP2RENn/gUm BhO2wrx9ZDuj+i4zlK4Bc9yE8ao/zp88NQFF4OOoM5gE31viZzwo49V3OK9pM2cg zdr4/f6XlM9G9BjI1zi3Vl7nTCCrYPkqQa6gmfE4ePRrKQEmk5sp1PwtjimV3aqg /Ru/jiBsRtU= =EfrN -----END PGP SIGNATURE-----