______________________________________________________________________________

                        SuSE Security Announcement

        Package:                ypbind/ypclient
        Announcement-ID:        SuSE-SA:2000:042
        Date:                   Wednesday, October 18th, 2000 19:15 MEST
        Affected SuSE versions: 6.0, 6.1, 6.2, 6.3, 6.4, 7.0
        Vulnerability Type:     possible remote root compromise
        Severity (1-10):        8
        SuSE default package:   yes (starting with SuSE-6.4)
        Other affected systems: Linux systems using this NIS implementation

    Content of this advisory:
        1) security vulnerability resolved: ypbind/ypclient
           problem description, discussion, solution and upgrade information
        2) pending vulnerabilities, solutions, workarounds
        3) standard appendix (further information)

______________________________________________________________________________

1)  problem description, brief discussion, solution, upgrade information

    Security problems have been found in the client code of the NIS 
    (Network Information System, aka yp - yellow pages) subsytem. 
    SuSE distributions before SuSE-6.1 came with the original ypbind
    program, SuSE-6.2 and later included the ypbind-mt NIS client 
    implementation. ypbind-3.3 (the earlier version) has a format
    string parsing bug if it is run in debug mode, and (discovered
    by Olaf Kirch <okir@caldera.de>) leaks file descriptors under 
    certain circumstances which can lead to a DoS. In addition, 
    ypbind-3.3 may suffer from buffer overflows. 
    ypbind-mt, the software shipped with SuSE distributions starting 
    with SuSE-6.2, suffers from a single format string parsing bug. 
    Some of these bugs could allow remote attackers to execute 
    arbitrary code as root.
    During code audit and testing it turned out that the ypbind-3.x 
    software in the SuSE-6.1 distribution and earlier needs a major
    overhaul to make it work both reliable and secure with respect
    to errors in the code. Basically, this is what happened when 
    Thorsten Kukuk <kukuk@suse.de> wrote ypbind-mt from scratch in 1998.
    For the same reason, we are currently unable to produce a working 
    security update package which fixes the known and yet unknown (there
    may be more) problems in the ypclient packages in the SuSE-6.1
    distribution and older.
    The only efficient workaround for the SuSE-6.1 distribution and older
    against these bugs for an untrusted, hostile environment is to upgrade
    to a new distribution base (SuSE-7.0 is recommended) and use the 
    ypclient update packages for this distribution.
    As of today, there is no exploit known to exist in the wild.

    For SuSE-6.2 and later distributions we provide update packages as 
    listed below. We recommend to download and install these packages
    on systems that are NIS/yp clients.
    Please note that the sources for the ypclient package are contained
    within the ypserv source rpm.

    Download the update package from locations described below and install 
    the package with the command `rpm -Uhv file.rpm'. The md5sum for each
    file is in the line below. You can verify the integrity of the rpm
    files using the command
        `rpm --checksig --nogpg file.rpm',
    independently from the md5 signatures below.


    i386 Intel Platform:

    SuSE-7.0
      
      76e4e7f60791db16c5e36fb5dbf60b65
    source rpm:
      
      e2b1dccaec003f54e4ebbdef84d99a10

    SuSE-6.4
      
      e485ea27264fb9c4f890cdf7605ffa30
    source rpm:
      
      c61c6df2ba1fef2369406b2dcbcd25f1

    SuSE-6.3
      
      c1a10cc0a3f72242b136be921f9ae0c1
    source rpm:
      
      6f47a880d5e7175dc2b5ff0116d7de4d

    SuSE-6.2
      
      9050e63cb9f7fac4997968760292a6f1
    source rpm:
      
      7ecfaffd8cdb68f73adfd1d6fd27ed39

    SuSE-6.1 and older:
    Please see the problem description above.


    Sparc Platform:

    SuSE-7.0
      
      1a38d25c8647f010e2a9879f28de4adf
    source rpm:
      
      6ba9200e49210f98ca845107b034b981



    AXP Alpha Platform:

    SuSE-6.4
      
      6aea95ca27245eb3df72da7596af3321
    source rpm:
      
      a4bf635b9ee4bdefc29b7e6e1cf0cf41

    SuSE-6.3
      
      b68f8690b7dc554ac9098c83f9c633cd
    source rpm:
      
      ef0a026d078847d0958118bbbc46b99e



    PPC Power PC Platform:

    SuSE-6.4
      
      26080b1443a3daa1de64c876ae36e6f2
    source rpm:
      
      4f0904d73c98c8b9737d5ac34b7a4dd5

______________________________________________________________________________

2)  Pending vulnerabilities in SuSE Distributions and Workarounds:

    Another security announcement is following this advisory.
______________________________________________________________________________

3)  standard appendix:

    SuSE runs two security mailing lists to which any interested party may
    subscribe:

    suse-security@suse.com
        -   general/linux/SuSE security discussion. 
            All SuSE security announcements are sent to this list.
            To subscribe, send an email to 
                <suse-security-subscribe@suse.com>.

    suse-security-announce@suse.com
        -   SuSE's announce-only mailing list.
            Only SuSE's security annoucements are sent to this list.
            To subscribe, send an email to
                <suse-security-announce-subscribe@suse.com>.

    For general information or the frequently asked questions (faq) 
    send mail to:
        <suse-security-info@suse.com> or
        <suse-security-faq@suse.com> respectively.

    ==============================================    SuSE's security contact is <security@suse.com>.
    ==============================================
Regards,
Roman Drahtmüller.
- - -- 
 -                                                                      -
| Roman Drahtmüller      <draht@suse.de> //          "Caution: Cape does |
  SuSE GmbH - Security           Phone: //       not enable user to fly."
| Nürnberg, Germany     +49-911-740530 // (Batman Costume warning label) |
 -                                                                      -
______________________________________________________________________________

    The information in this advisory may be distributed or reproduced,
    provided that the advisory is not modified in any way.
    SuSE GmbH makes no warranties of any kind whatsoever with respect 
    to the information contained in this security advisory.

Type Bits/KeyID    Date       User ID
pub  2048/3D25D3D9 1999/03/06 SuSE Security Team <security@suse.de>

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