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

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 __________________________________________________________
 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 
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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>
	
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 at:
	<URL:http://sunsolve.sun.com/sunsolve/secbulletins/SunSCkey.txt>
		 	 	 
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 - Your local Sun answer centers
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________________________________________________________________________________
Copyright 1998 Sun Microsystems, Inc. All rights reserved. Sun, 
Sun Microsystems, Solaris and SunOS are trademarks or registered trademarks 
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Security Bulletin may be reproduced and distributed, provided that this 
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[ End Sun Microsystems Advisory ]
______________________________________________________________________________
CIAC wishes to acknowledge the contributions of CERT for the information
contained in this bulletin.
______________________________________________________________________________
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H-100: SunOS, Solaris libXt Vulnerability
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H-103: HP-UX X11/Motif Libraries Vulnerability
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