SuSE Linux Advisory: heartbeat


                        SuSE Security Announcement

        Package:                heartbeat
        Announcement-ID:        SuSE-SA:2002:037
        Date:                   Monday, Oct 14, 12:00 UTC
        Affected products:      8.0, 8.1
        Vulnerability Type:     remote root
        Severity (1-10):        7
        SuSE default package:   yes
        Cross References:       http://linux-ha.org/security/sec01.txt

    Content of this advisory:
        1) security vulnerability resolved: format string bug in heartbeat
           problem description, discussion, solution and upgrade information
        2) pending vulnerabilities, solutions, workarounds:
            - util-linux
            - dhcpcd
            - heimdal
            - logsurfer
            - ghostscript
        3) standard appendix (further information)


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

    Heartbeat is a monitoring service that is used to implement
    failover in high-availablity environments. It can be configured to
    monitor other systems via serial connections, or via UDP/IP.

    Several format string bugs have been discovered in the heartbeat
    package.  One of these format string bugs is in the normal path
    of execution, all the remaining ones can only be triggered if
    heartbeat is running in debug mode. Since heartbeat is running with
    root privilege, this problem can possibly be exploited by remote
    attackers, provided they are able to send packets to the UDP port
    heartbeat is listening on (port 694 by default).

    Vulnerable versions of heartbeat are included in SuSE Linux 8.0 and
    SuSE Linux 8.1.

    As a workaround, make sure that your firewall blocks all traffic
    to the heartbeat UDP port.

    The proper fix is to upgrade to the packages provided by SuSE.
    In addition to fixing the format string bug, this update also
    changes heartbeat to perform processing of network packets as
    user "nobody" instead of root. The update package for SuSE Linux
    8.1 also fixes a boot time problem with heartbeat.

    SuSE wishes to thank Nathan Wallwork for reporting the bug, and Alan
    Robertson for his assistance in dealing with this problem. For more
    information on this vulnerability, please refer to

    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.

    i386 Intel Platform:

        - being rebuilt

    source rpm:


2)  Pending vulnerabilities in SuSE Distributions and Workarounds:

    - util/util-linux
    The mount and umount program did not set their umask properly before
    creating the mtab file. Local attackers could abuse the mount program
    to put arbitrary content into the /etc/mtab file. New packages are
    available on our ftp servers which fix this problem. An update is

    - dhcpcd
    The dhcpcd DHCP client daemon has the ability to execute an
    external script named /sbin/dhcpcd-<interface>.exe when assigning
    a new IP address.  It is not installed by default, however.

    The script obtains the DHCP information by sourcing a file named
    /var/lib/dhcpcd/dhcpcd-<interface>.info, containing a list
    of shell variable assignments. Insufficient quoting of these
    assignments allowed malicious DHCP servers (or attackers able
    to spoof DHCP responses) to execute arbitrary shell commands on
    the DHCP client if the user had installed the script.

    - heimdal
    Within the SuSE Advisory SuSE-SA:2002:034 regarding the Heimdal packages,
    the following rpm was missing in the list:


    If you updated the Heimdal packgages for SuSE 7.3-i386, make sure you also
    update this package.

    - logsurfer
    New logsurfer (logsurf in SuSE-7.0) packages are available for
    download. These packages fix two errors (off-by-one overflow,
    uninitialized memory) in the logsurfer package that can lead to
    a crash of the program, resulting in a denial of service.  It is
    unknown if the two bugs can be used to execute arbitrary code in
    the context of the logsurfer program.

    - ghostscript (CVE CAN-2002-0363)
    In ghostscript 6.50, setting the interpreter to SAFE mode was
    reversible. This could be exploited to subvert the accounts of
    users viewing malicious PostScript[tm], as well as the lp acount
    if the print system was enabled.
    SuSE has released updated RPMs for SuSE Linux 7.3 and SuSE Linux
    Enterprise Server 7 for PowerPC. No other SuSE platform is affected.

    - gv/ggv/kghostview (CVE CAN-2002-0832)
    The ghostview (gv) code had several buffer overflows when handling
    PostScript[tm] structural comments. These were also present in the
    GNOME and KDE PostScript viewers derived from it. SuSE has released
    fixed packages for these vulnerabilities.


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>

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