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SuSE Linux Advisory: heimdal

Oct 01, 2002, 00:59 (0 Talkback[s])

                        SuSE Security Announcement

        Package:                heimdal
        Announcement-ID:        SuSE-SA:2002:034
        Date:                   Mon Sep 30 17:00:00 CEST 2002
        Affected products:      SuSE Linux 7.2, 7.3, 8.0,
                                SuSE eMail Server,
                                SuSE Linux Connectivity Server,
                                SuSE Linux Enterprise Server 7,
                                SuSE Linux Office Server
        Vulnerability Type:     remote command execution
        Severity (1-10):        8
        SuSE default package:   Yes
        Cross References:       http://www.pdc.kth.se/heimdal

    Content of this advisory:
        1) security vulnerability resolved: Various overflows in heimdal.
           problem description, discussion, solution and upgrade information
        2) pending vulnerabilities, solutions, workarounds:
            - ghostview/kghostview
            - fetchmail
        3) standard appendix (further information)


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

    The Heimdal package is a free Kerberos implementation offering flexible
    authentication mechanisms based on the Kerberos 5 and Kerberos 4 scheme.
      The SuSE Security Team has reviewed critical parts of the Heimdal
    package such as the kadmind and kdc server. While doing so several
    possible buffer overflows and other bugs have been uncovered and fixed.
    Remote attackers can probably gain remote root access on unpatched systems.
    Since these services run usually on authentication servers we consider
    these bugs to be very serious. An update is strongly recommended if you are
    using the Heimdal package.

    Please download the update package for your distribution and verify its
    integrity by the methods listed in section 3) of this announcement.
    Then, install the package using the command "rpm -Fhv file.rpm" to apply
    the update.
    Our maintenance customers are being notified individually. The packages
    are being offered to install from the maintenance web.

    To be sure the update takes effect you have to restart the services which
    belong to the heimdal package. As root execute the command

       /etc/rc.d/kdc restart

    If you are running other Kerberos based services such as hpropd make sure
    you also restart them as well.

    i386 Intel Platform:

    source rpm:

    source rpm:

    source rpm:

    Sparc Platform:

    source rpm:

    PPC Power PC Platform:

    source rpm:


2)  Pending vulnerabilities in SuSE Distributions and Workarounds:

    - ghostview/kghostview
    Bufferoverflows have recently been discovered in these packages. They allow
    attackers to execute arbitrary code with the privileges of the user
    viewing special crafted documents created by the attacker. New packgaes will
    soon be available on our ftp servers.

    - fetchmail
    Fetchmail contains remotely exploitable overflows in the mail header
    parsing functions. In depth discussion of these problems can be found at
    New packages will soon be available on our ftp servers.


3)  standard appendix: authenticity verification, additional information

  - Package authenticity verification:

    SuSE update packages are available on many mirror ftp servers all over
    the world. While this service is being considered valuable and important
    to the free and open source software community, many users wish to be
    sure about the origin of the package and its content before installing
    the package. There are two verification methods that can be used
    independently from each other to prove the authenticity of a downloaded
    file or rpm package:
    1) md5sums as provided in the (cryptographically signed) announcement.
    2) using the internal gpg signatures of the rpm package.

    1) execute the command
        md5sum <name-of-the-file.rpm>
       after you downloaded the file from a SuSE ftp server or its mirrors.
       Then, compare the resulting md5sum with the one that is listed in the
       announcement. Since the announcement containing the checksums is
       cryptographically signed (usually using the key security@suse.de),
       the checksums show proof of the authenticity of the package.
       We disrecommend to subscribe to security lists which cause the
       email message containing the announcement to be modified so that
       the signature does not match after transport through the mailing
       list software.
       Downsides: You must be able to verify the authenticity of the
       announcement in the first place. If RPM packages are being rebuilt
       and a new version of a package is published on the ftp server, all
       md5 sums for the files are useless.

    2) rpm package signatures provide an easy way to verify the authenticity
       of an rpm package. Use the command
        rpm -v --checksig <file.rpm>
       to verify the signature of the package, where <file.rpm> is the
       filename of the rpm package that you have downloaded. Of course,
       package authenticity verification can only target an un-installed rpm
       package file.
        a) gpg is installed
        b) The package is signed using a certain key. The public part of this
           key must be installed by the gpg program in the directory
           ~/.gnupg/ under the user's home directory who performs the
           signature verification (usually root). You can import the key
           that is used by SuSE in rpm packages for SuSE Linux by saving
           this announcement to a file ("announcement.txt") and
           running the command (do "su -" to be root):
            gpg --batch; gpg < announcement.txt | gpg --import
           SuSE Linux distributions version 7.1 and thereafter install the
           key "build@suse.de" upon installation or upgrade, provided that
           the package gpg is installed. The file containing the public key
           is placed at the top-level directory of the first CD (pubring.gpg)
           and at ftp://ftp.suse.com/pub/suse/pubring.gpg-build.suse.de .

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

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

        -   SuSE's announce-only mailing list.
            Only SuSE's security announcements are sent to this list.
            To subscribe, send an email to

    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> or <security@suse.de>.
    The <security@suse.de> public key is listed below.

    The information in this advisory may be distributed or reproduced,
    provided that the advisory is not modified in any way. In particular,
    it is desired that the clear-text signature shows proof of the
    authenticity of the text.
    SuSE Linux AG makes no warranties of any kind whatsoever with respect
    to the information contained in this security advisory.

Type Bits/KeyID    Date       User ID
pub  2048R/3D25D3D9 1999-03-06 SuSE Security Team <security@suse.de>
pub  1024D/9C800ACA 2000-10-19 SuSE Package Signing Key <build@suse.de>