Visit our newest sister site!
Hundreds of free aircraft flight manuals
Civilian • Historical • Military • Declassified • FREE!


TUCoPS :: Unix :: General :: ciach107.txt

Unix Buffer Overflow Rdist Vulnerability




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

             __________________________________________________________

                       The U.S. Department of Energy
                    Computer Incident Advisory Capability
                           ___  __ __    _     ___
                          /       |     /_\   /
                          \___  __|__  /   \  \___
             __________________________________________________________

                             INFORMATION BULLETIN

                  UNIX Buffer Overflow in rdist Vulnerability

November 20, 1998 17:00 GMT                                      Number H-107
______________________________________________________________________________
PROBLEM:       A new vulnerability has been found in some set-user-id root
               implementations of rdist.
PLATFORM:      UNIX operating systems - vendors are listed below in Section
               III.
DAMAGE:        This vulnerability may allow local users to gain root
               privileges.
SOLUTION:      Apply a vendor patch or a freely available version of rdist
               that does not need to be installed as set-user-id root.
VULNERABILITY  Exploit information involving these vulnerabilities have been
ASSESSMENT:    made publicly available.
______________________________________________________________________________

[ Updated November 20, 1998 with additional patch information from Sun
  Microsystems, Inc. ]


[ Start CERT Advisory ]

=============================================================================
CERT* Advisory CA-97.23
Original issue date: September 16, 1997
Last revised: --

Topic: Buffer Overflow Problem in rdist
- ------------------------------------------------------------------------------

The CERT Coordination Center has received reports of a vulnerability in rdist
that enables anyone with access to a local account to gain root privileges.
This is not the same vulnerability as the one discussed in CA-96.14.

Section III.A contains instructions on how to determine if your site is
vulnerable. If your implementation of rdist is vulnerable, the CERT/CC team
encourages you to follow your vendor's instructions (Sec. III.B and Appendix
A) or install a freely available version of the rdist program that is not
installed as set-user-id root and is, therefore, not susceptible to the
exploitation described in this advisory (Sec. III.C).

For information on the earlier problem with rdist, see
      ftp://info.cert.org/pub/cert_advisories/CA-96.14.rdist_vul

We will update this advisory as we receive additional information.
Please check our advisory files regularly for updates that relate to your
site.

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

I.   Description

     The rdist program is a UNIX Operating System utility used to
     distribute files from one host to another. On some systems, rdist
     opens network connections using a privileged port as the source port.
     This requires root privileges, and to attain these privileges rdist on
     such systems is installed set-user-id root.

     A new vulnerability has been found in some set-user-id root
     implementations of rdist. The vulnerability lies in the function
     expstr(), where macros supplied as arguments are expanded using
     sprintf(). It is possible to overwrite stack frames and call specially
     pre-crafted native machine code. If the appropriate machine code is
     supplied, an attacker can execute arbitrary programs (such as the
     shell) with set-user-id root privileges.

     Note that this vulnerability is distinct from that discussed in CERT
     advisory CA-96.14.


II.  Impact

     On systems with a vulnerable copy of rdist, anyone with access to a
     local account can gain root access.


III. Solution

     We urge you to follow the steps in Section A to determine if your
     system is vulnerable and, if it is, to turn off rdist while you decide
     how to proceed.

     If your system is vulnerable and you need the functionality that rdist
     provides, you should install a vendor patch (Section B). Until you can
     do so, you may want to use a freely available version of rdist that
     does not need to be installed as set-user-id root and is, therefore,
     not susceptible to the exploitation described in this advisory
     (Section C).

     A. How to check for set-user-id root versions of rdist

        To find set-user-id root versions of rdist and to disable the
        programs that are possibly vulnerable, use the following find
        command or a variant. Consult your local system documentation to
        determine how to tailor the find program on your system.

        You will need to run the find command on each system you maintain
        because the command examines files on the local disk only.
        Substitute the names of your local file systems for
        FILE_SYSTEM_NAMES in the example. Example local file system names
        are /, /usr, and /var. You must do this as root.

        Note that this is one long command, though we have separated
        it onto three lines using backslashes.

             find FILE_SYSTEM_NAMES -xdev -type f -user root \
                    -name '*rdist*' -perm -04000 -exec ls -l '{}' \; \
                    -ok chmod 0500 '{}' \;

        This command will find all files on a system that
            - are only in the file system you name (FILE_SYSTEM_NAMES -xdev)
            - are regular files (-type f)
            - are owned by root (-user root)
            - have "rdist" as a component of the name (-name '*rdist*')
            - are setuid (-perm -04000)

        Once found, those files will
            - have their names and details printed (-exec ls -l '{}')
            - have the setuid mode removed (making the file available
              only to root) but only if you type `y' in response to the
              prompt (-ok chmod 0500 '{}' \;)

     B. Obtain and install the appropriate patch

        Below is a list of vendors who have provided information for this
        advisory. Details are in Appendix A, and we will update the appendix
        as we receive more information.

               Berkeley Software Design, Inc. (BSDI)
               Digital Equipment Corp.
               FreeBSD, Inc.
               Hewlett-Packard Company
               IBM Corporation
               NEC Corporation
               The Santa Cruz Operation, Inc. (SCO)
               Siemens-Nixdorf
               Silicon Graphics Inc. (SGI)
               Sun Microsystems, Inc.

        If your vendor's name is not on this list, please contact the
        vendor directly.

     C. If you need the functionality that rdist provides but a patched
        version is not yet available from your vendor, consider installing
        rdist-6.1.3, which is freely available from

              ftp://usc.edu/pub/rdist/rdist-6.1.3.tar.gz

              MD5 (rdist-6.1.3.tar.gz) = 8a76b880b023c5e648b7cb77b9608b9f

        The README file in the distribution explains how to configure and
        install this version of rdist.

        We recommend that you configure this version of rdist to use rsh
        instead of rcmd. Here is the relevant text from the README:

            By default rdist uses rsh(1c) to make connections to remote
            hosts. This has the advantage that rdist does not need to be
            setuid to "root". This eliminates most potential security
            holes. It has the disadvantage that it takes slightly more time
            for rdist to connect to a remote host due to the added overhead
            of doing a fork() and then running the rsh(1c) command.

        Some sites with sufficient expertise use the ssh program in
        conjunction with rdist, instead of using rcmd or rsh. If you have
        the expertise, you may want to implement this configuration.

        For further details on this option see "Ssh (Secure Shell) FAQ -
        Frequently asked questions," Section 4.4, "Can I use rdist with ssh?"
        It is available from

                http://www.uni-karlsruhe.de/~ig25/ssh-faq/ssh-faq-4.html

        For details on how to obtain ssh, see FAQ Section 3.4, "Where can I
        obtain ssh?" This section can be found in

            http://www.uni-karlsruhe.de/~ig25/ssh-faq/ssh-faq-3.html


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

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)
=====================================
  BSDI shipped a patch for this for our 2.1 release (U210-018) when
  the original Bugtraq advisory was released.  The 3.0 version of
  rdist is not vulnerable and in fact is no longer even setuid.


Digital Equipment Corp.
=======================
  This reported problem is not present for Digital's ULTRIX or Digital UNIX
  Operating Systems Software.

                                DIGITAL EQUIPMENT CORPORATION
                                -----------------------------

FreeBSD, Inc.
=============
  2.1.0 is vulnerable.
  2.1.5, 2.1.6 and 2.1.7 are and 2.1-stable are not. In any case, upgrading
  to 2.1.7 or even better, 2.1-stable should be considered.
  If there is demand, we'll release a patch for 2.1.0

  All 2.2 releases, 2.2-stable and FreeBSD-current are not vulnerable.


Hewlett-Packard Company
=======================
  HP is -not- vulnerable; the problem didn't exist in 9.X, and has been fixed
  in 10.X with Security Bulletin #36 (HPSBUX9608-036) last year.  Patch
  numbers change frequently because of cumulative patching, so please check
  current patch ID information either by bulletin or by platform/release at
  our HP Electronic Support Center in the "Security Patch Matrix," which is
  updated every 24 hours.

 1)  From your Web browser, access the URL:

       http://us-support.external.hp.com (US,Canada,Asia-Pacific,
       and Latin-America)

       http://europe-support.external.hp.com  (Europe)

 2)  On the HP Electronic Support Center main screen, select the
     hyperlink "Support Information Digests".


 3)  On the "Welcome to HP's Support Information Digests" screen,
     under the heading "Register Now", select the appropriate hyperlink
     "Americas and Asia-Pacific", or "Europe".

 4)  On the "New User Registration" screen, fill in the fields
     for the User Information and Password and then select the button
     labeled "Submit New User".

 5)  On the "User ID Assigned" screen, select the hyperlink
     "Support Information Digests".

  **Note what your assigned user ID and password are for future
  reference.

 6)  You should now be on the "HP Support Information Digests Main"
     screen.  You might want to verify that your email address is
     correct as displayed on the screen.  From this screen, you may
     also view/subscribe to the digests, including the security
     bulletins digest.

     To get a patch matrix of current HP-UX and BLS security
     patches referenced by either Security Bulletin or Platform/OS,
     click on following screens in order:
        Technical Knowledge Database
        Browse the HP Security Bulletins Archive
        HP-UX Security Patch Matrix


IBM Corporation
===============
  All versions of AIX are vulnerable to this buffer overflow.  There is
  no 3.2 fix.  It is recommended that 3.2 customers upgrade to a higher
  level.  The following APARs will be available for AIX version 4
  soon.

  AIX 3.2:  upgrade to 4.1.5 or higher
  AIX 4.1:  IX70876
  AIX 4.2:  IX70875

   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.


NEC Corporation
===============
  The following systems are NOT affected by this vulnerability:

        UX/4800
        UX/4800(64)
        EWS-UX/V(Rel4.2MP)
        EWS-UX/V(Rel4.2)
        UP-UX/V(Rel4.2MP)

  To report a new vulnerability, contact <UX48-security-support@nec.co.jp>.


The Santa Cruz Operation, Inc. (SCO)
====================================
  SCO has determined that the following SCO operating systems are
  not vulnerable:

  - SCO CMW+ 3.0
  - SCO Open Desktop/Open Server 3.0
  - SCO OpenServer 5.0
  - SCO UnixWare 2.1


Siemens-Nixdorf Informationssysteme AG
======================================
  Siemens-Nixdorf does not ship rdist.


Silicon Graphics Inc. (SGI)
===========================
  At this time, Silicon Graphics does not have any public information for the
  rdist buffer overflow issue.  Silicon Graphics has communicated with CERT/CC
  and other external security parties and is actively investigating this
  issue.  When more Silicon Graphics information (including any possible
  patches) is available for release, that information will be released via the
  SGI security mailing list, wiretap.

  For subscribing to the wiretap mailing list and other SGI security related
  information, please refer to the Silicon Graphics Security Headquarters
  website located at:

             http://www.sgi.com/Support/security/security.html


Sun Microsystems, Inc.
======================
  We are producing patches.

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

The CERT Coordination Center thanks Hiroshi Nakano of Ryukoku University,
Japan for reporting this problem. We also thank Wolfgang Ley of DFN-CERT
for his assistance with the Solutions section of the advisory.

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


[ End CERT Advisory ]

[ Start Sun Microsystems Advisory ]

________________________________________________________________________________
 		   Sun Microsystems, Inc. Security Bulletin
 		
Bulletin Number:	#00179
Date: 			November 18, 1998
Cross-Ref:		
Title:			rdist 
________________________________________________________________________________

The information contained in this Security Bulletin is provided "AS IS." 
Sun makes no warranties of any kind whatsoever with respect to the information 
contained in this Security Bulletin. ALL EXPRESS OR IMPLIED CONDITIONS, 
REPRESENTATIONS AND WARRANTIES, INCLUDING ANY WARRANTY OF NON-INFRINGEMENT OR 
IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE 
HEREBY DISCLAIMED AND EXCLUDED TO THE EXTENT ALLOWED BY APPLICABLE LAW.

IN NO EVENT WILL SUN MICROSYSTEMS, INC. BE LIABLE FOR ANY LOST REVENUE, 
PROFIT OR DATA, OR FOR DIRECT, SPECIAL, INDIRECT, CONSEQUENTIAL, INCIDENTAL 
OR PUNITIVE DAMAGES HOWEVER CAUSED AND REGARDLESS OF ANY THEORY OF LIABILITY 
ARISING OUT OF THE USE OF OR INABILITY TO USE THE INFORMATION CONTAINED IN 
THIS SECURITY BULLETIN, EVEN IF SUN MICROSYSTEMS, INC. HAS BEEN ADVISED OF 
THE POSSIBILITY OF SUCH DAMAGES.

If any of the above provisions are held to be in violation of applicable law, 
void, or unenforceable in any jurisdiction, then such provisions are waived 
to the extent necessary for this disclaimer to be otherwise enforceable in 
such jurisdiction.
________________________________________________________________________________

1.  Background

    The rdist program is a setuid root utility that distributes files
    from one host to another. Several buffer overflow vulnerabilities
    have been discovered which could be exploited by an attacker to 
    gain root access.
    
2.  Affected Supported Versions
        
    Solaris(tm) versions:   2.6, 2.6_x86, 2.5.1, 2.5.1_x86, 2.5, 2.5_x86,
                            2.4, 2.4_x86 and 2.3 
                   
    SunOS(tm) versions:     4.1.4 and 4.1.3_U1
    
3.  Recommendations

    Sun recommends that you install the respective patches immediately
    on affected systems.
    
    Operating System	Patch ID	
    _________________   _________    
    Solaris 2.6         105667-02		
    Solaris 2.6_x86     105668-02
    Solaris 2.5.1       103817-03
    Solaris 2.5.1_x86   103818-03
    Solaris 2.5         103815-03
    Solaris 2.5_x86     103816-03
    Solaris 2.4         103813-03
    Solaris 2.4_x86     103814-03
    Solaris 2.3         101494-04
    SunOS 4.1.4         103824-04
    SunOS 4.1.3_U1      103823-04

_______________________________________________________________________________
APPENDICES

A.  Patches listed in this bulletin are available to all Sun customers via 
    World Wide Web at:
    
    	<URL:http://sunsolve.sun.com/sunsolve/pubpatches/patches.html>

B.  Checksums for the patches listed in this bulletin are available via 
    World Wide Web at:

    	<URL:http://sunsolve.sun.com/sunsolve/pubpatches/patches.html>

C.  Sun security bulletins are available via World Wide Web at:

	<URL:http://sunsolve.sun.com/sunsolve/secbulletins>
	
D.  Sun Security Coordination Team's PGP key is available via World Wide Web 
    at:

	<URL:http://sunsolve.sun.com/sunsolve/secbulletins/SunSCkey.txt>
		    	    	    
E.  To report or inquire about a security problem with Sun software, contact 
    one or more of the following:
  
        - Your local Sun answer centers
        - Your representative computer security response team, such as CERT 
        - Sun Security Coordination Team. Send email to:
	 
     		security-alert@sun.com

F.  To receive information or subscribe to our CWS (Customer Warning System) 
    mailing list, send email to:
    
    		security-alert@sun.com
   
    with a subject line (not body) containing one of the following commands:

        Command         Information Returned/Action Taken
        _______         _________________________________

        help            An explanation of how to get information
        
        key             Sun Security Coordination Team's PGP key
	
        list            A list of current security topics

        query [topic]   The email is treated as an inquiry and is forwarded to 
                        the Security Coordination Team

        report [topic]  The email is treated as a security report and is
                        forwarded to the Security Coordination Team. Please 
                        encrypt sensitive mail using Sun Security Coordination
                        Team's PGP key

        send topic      A short status summary or bulletin. For example, to 
                        retrieve a Security Bulletin #00138, supply the 
                        following in the subject line (not body):
        		
                                send #138

        subscribe       Sender is added to our mailing list.  To subscribe, 
                        supply the following in the subject line (not body):

                            	subscribe cws your-email-address
			
                        Note that your-email-address should be substituted
                        by your email address.
			
        unsubscribe     Sender is removed from the CWS mailing list.
________________________________________________________________________________

Copyright 1998 Sun Microsystems, Inc. All rights reserved. Sun, 
Sun Microsystems, Solaris and SunOS are trademarks or registered trademarks 
of Sun Microsystems, Inc. in the United States and other countries. This 
Security Bulletin may be reproduced and distributed, provided that this 
Security Bulletin is not modified in any way and is attributed to 
Sun Microsystems, Inc. and provided that such reproduction and distribution 
is performed for non-commercial purposes.



[ End Sun Microsystems Advisory ]

______________________________________________________________________________

CIAC wishes to acknowledge the contributions of CERT for the information
contained in this bulletin.
______________________________________________________________________________


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.

CIAC services are available to DOE, DOE contractors, and the NIH. CIAC
can be contacted at:
    Voice:    +1 510-422-8193
    FAX:      +1 510-423-8002
    STU-III:  +1 510-423-2604
    E-mail:   ciac@llnl.gov

For emergencies and off-hour assistance, DOE, DOE contractor sites,
and the NIH may contact CIAC 24-hours a day. During off hours (5PM -
8AM PST), call the CIAC voice number 510-422-8193 and leave a message,
or call 800-759-7243 (800-SKY-PAGE) to send a Sky Page. CIAC has two
Sky Page PIN numbers, the primary PIN number, 8550070, is for the CIAC
duty person, and the secondary PIN number, 8550074 is for the CIAC
Project Leader.

Previous CIAC notices, anti-virus software, and other information are
available from the CIAC Computer Security Archive.

   World Wide Web:      http://ciac.llnl.gov/
   Anonymous FTP:       ciac.llnl.gov (198.128.39.53)
   Modem access:        +1 (510) 423-4753 (28.8K baud)
                        +1 (510) 423-3331 (28.8K baud)

CIAC has several self-subscribing mailing lists for electronic
publications:
1. CIAC-BULLETIN for Advisories, highest priority - time critical
   information and Bulletins, important computer security information;
2. CIAC-NOTES for Notes, a collection of computer security articles;
3. SPI-ANNOUNCE for official news about Security Profile Inspector
   (SPI) software updates, new features, distribution and
   availability;
4. SPI-NOTES, for discussion of problems and solutions regarding the
   use of SPI products.

Our mailing lists are managed by a public domain software package
called Majordomo, which ignores E-mail header subject lines. To
subscribe (add yourself) to one of our mailing lists, send the
following request as the E-mail message body, substituting
ciac-bulletin, ciac-notes, spi-announce OR spi-notes for list-name:

E-mail to       ciac-listproc@llnl.gov or majordomo@tholia.llnl.gov:
        subscribe list-name
  e.g., subscribe ciac-notes

You will receive an acknowledgment email immediately with a confirmation
that you will need to mail back to the addresses above, as per the
instructions in the email.  This is a partial protection to make sure
you are really the one who asked to be signed up for the list in question.

If you include the word 'help' in the body of an email to the above address,
it will also send back an information file on how to subscribe/unsubscribe,
get past issues of CIAC bulletins via email, etc.

PLEASE NOTE: Many users outside of the DOE, ESnet, and NIH computing
communities receive CIAC bulletins.  If you are not part of these
communities, please contact your agency's response team to report
incidents. Your agency's team will coordinate with CIAC. 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 via WWW at http://www.first.org/.

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.

LAST 10 CIAC BULLETINS ISSUED (Previous bulletins available from CIAC)

H-97: SGI IRIX ftpd Signal Handling Vulnerability
H-98: SunOS automounter Vulnerability
H-99: SunOS, Solaris ifconfig ioctls Vulnerability
H-100: SunOS, Solaris libXt Vulnerability
H-101: FreeBSD procfs Vulnerability
H-102: SGI IRIX webdist.cgi, handler and wrap programs Vulnerabilities
H-103: HP-UX X11/Motif Libraries Vulnerability
H-104: HP-UX libXt Vulnerability
H-105: HP-UX vuefile, vuepad, dtfile, & dtpad Vulnerabilities
H-106: SGI IRIX LOCKOUT & login/scheme Vulnerabilities


-----BEGIN PGP SIGNATURE-----
Version: 4.0 Business Edition

iQCVAwUBNCBhV7nzJzdsy3QZAQEe3AQAs7KjXHWKRei3l8YlGd878tgsy5IIVH24
GPhP+Oeak7fQ4wG1SYGqTurbwpJxerOfOwVWXkPCUE7aIlutY+SVXH11Am5h0/6z
n5XHiAGbIY+Q1DQBK2yU7obGttvrGdLERMt5JIlcRnnWcmx1wmhkJp3cjLDy7PSr
b3rRCZsRpqU=
=8my1
-----END PGP SIGNATURE-----


TUCoPS is optimized to look best in Firefox® on a widescreen monitor (1440x900 or better).
Site design & layout copyright © 1986-2014 AOH