-----BEGIN PGP SIGNED MESSAGE-----

Hash: SHA1





=============================================================================

CERT* Advisory CA-97.10

Original issue date: April 24, 1997

Last Revised: September 26, 1997

              Updated copyright statement



              A complete revision history is at the end of this file.





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

==========================================

  This problem has been resolved with code that is available in released

  software packages as described in the FIX AVAILABILITY section below.



  FIX AVAILABILITY

  ----------------



  For each affected product level, the following table identifies the release

  that contains the fix:



                          Release Levels

  Affected Product        Containing Fix

  ================        ==============

  UNICOS                  UNICOS 9.0.2.5

                          UNICOS 9.2.0.4

  UNICOS/mk               UNICOS/mk 1.5.1

  UNICOS MAX              UNICOS MAX 1.3.0.5





  RELATED INFORMATION

  -------------------



  SPR 704175      POSSIBLE SECURITY PROBLEM IN SETLOCALE







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



     http://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

         http://info.cert.org/pub/CERT_PGP.key



Getting security information

   CERT publications and other security information are available from

        http://www.cert.org/

        http://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. Conditions for use, disclaimers,

and sponsorship information can be found in

http://www.cert.org/legal_stuff.html and http://ftp.cert.org/pub/legal_stuff .

If you do not have FTP or web access, send mail to cert@cert.org with

"copyright" in the subject line.



CERT is registered in the U.S. Patent and Trademark Office.





- ---------------------------------------------------------------------------



This file: http://info.cert.org/pub/cert_advisories/CA-97.10.nls

           http://www.cert.org

               click on "CERT Advisories"



=============================================================================

UPDATES



There appear to be several slightly different descriptions for the NLS

acronym.  They are included here for convenience:



        National Language Service

        National Language Support

        Native Language System

        Natural Language Service

        Natural Language Support



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Revision history



Sep. 26, 1997  Updated copyright statement

June 3, 1997  Updates section - added other phrases for the the NLS acronym

              Appendix A - updated Cray Research entry.

May 1, 1997   Section III and Appendex.  Updated vendor information for

                 Hewlett-Packard Company.

              Acknowledgments - added a name upon receiving permission to do

                 so.





-----BEGIN PGP SIGNATURE-----

Version: PGP for Personal Privacy 5.0

Charset: noconv



iQA/AwUBOBS/fFr9kb5qlZHQEQLc+QCgiQO8uAPVHu/JO5ZogN6UZB2vKpkAoJ7y

NGIlcWSxKWzZsiSyDxxSRXFM

=yndw

-----END PGP SIGNATURE-----