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______________________________________________________________________________

                        SUSE Security Announcement

        Package:                libpng
        Announcement-ID:        SUSE-SA:2004:023
        Date:                   Wednesday, Aug 4th 2004 16:00 MEST
        Affected products:      8.0, 8.1, 8.2, 9.0, 9.1
                                SUSE Linux Database Server,
                                SUSE eMail Server III, 3.1
                                SUSE Linux Enterprise Server 7, 8, 9
                                SUSE Linux Firewall on CD/Admin host
                                SUSE Linux Connectivity Server
                                SUSE Linux Office Server
        Vulnerability Type:     remote system compromise
        Severity (1-10):        9
        SUSE default package:   yes
        Cross References:       VU#388984
                                VU#236656
                                VU#160448
                                VU#477512
                                VU#817368
                                VU#286464
                                CAN-2004-0597
                                CAN-2004-0598
                                CAN-2004-0599

    Content of this advisory:
        1) security vulnerability resolved:
             - stack based buffer overflows
             - NULL pointer dereference
             - integer overflows
           problem description
        2) solution/workaround
        3) special instructions and notes
        4) package location and checksums
        5) pending vulnerabilities, solutions, workarounds:
            - mod_ssl
            - lha
            - gfxboot
            - liby2util
            - pure-ftpd
            - neon
            - pavuk
            - sox
            - gaim
            - kernel
        6) standard appendix (further information)

______________________________________________________________________________

1) problem description, brief discussion

    Several different security vulnerabilities were found in the PNG
    library which is used by applications to support the PNG image format.

    A remote attacker is able to execute arbitrary code by triggering a
    buffer overflow due to the incorrect handling of the length of
    transparency chunk data and in other pathes of image processing.
    (VU#388984, VU#817368, CAN-2004-0597)
    A special PNG image can be used to cause an application crashing due
    to NULL pointer dereference in the function png_handle_iCPP() (and
    other locations). (VU#236656, CAN-2004-0598)
    Integer overflows were found in png_handle_sPLT(), png_read_png()
    functions and other locations. These bugs may at least crash an
    application. (VU#160448, VU#477512, VU#286464, CAN-2004-0599)

    Many thanks to Chris Evans who reported issues to us and other vendors.


3) special instructions and notes

    Various applications use libpng either dynamically linked, statically
    linked, or by linking a copy of libpng included in the application's
    source distribution.
    In the first case you have to restart the affected application.
    In the other cases we will release updates for these packages if the
    vulnerable libpng code is called with input from an untrusted source.


4) package location and checksums

    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.

    x86 Platform:

    SUSE Linux 9.1:
          0e89a04a0a50a49f756795bbd319e1dd
    patch rpm(s):
          dc7270f4c0c728c3ba7252d0a551e437
    source rpm(s):
          bb8d8000a010d92747dda1b0908d41aa

    SUSE Linux 9.0:
          5b34c70a715cd34bb0e5879063dcf63b
    patch rpm(s):
          6c192934eae546bc1f2c9b7980c848f0
    source rpm(s):
          c740a8c8c6188470512c91ec8e9e70a9

    SUSE Linux 8.2:
          64d76d67104123317c4a66a0721072e8
    patch rpm(s):
          372b2eae57ff3ff90ad1250e8a2d3a91
    source rpm(s):
          16dde1bf26f8c9c006ccad4779d138d7

    SUSE Linux 8.1:
          88dc17c0edccfcd65fea3539379de370
    patch rpm(s):
          24d8632e5454e46ce4623c5a672a3d5d
    source rpm(s):
          e3086525ee914ddc5dc0c7da7ab96a25

    SUSE Linux 8.0:
          09b22a2fab61b1018ce73e2965777123
    patch rpm(s):
          097de7e1c11106390128b6996041fe3c
    source rpm(s):
          9e1da14f139fc4dcf481cdf836397da7



    x86-64 Platform:

    SUSE Linux 9.1:
          c6c0f425059cf94803952530f0e9ba02
    patch rpm(s):
          01814d5c445560c6bcca0f1d9221e5be
    source rpm(s):
          27c4236b2ca11a760b3028c5058db7cf

    SUSE Linux 9.0:
          5e8c7dcfe20c386150c4129bb549569f
    patch rpm(s):
          4fc9a5a29f5c813b32b9dee230250b17
    source rpm(s):
          526c0048344f1aa467903b1a8bce3506

______________________________________________________________________________

5)  Pending vulnerabilities in SUSE Distributions and Workarounds:

    - mod_ssl
    A remotely exploitable format string bug has been found in the
    logging function of mod_ssl.
    New packages are available at our FTP servers.

    - lha
    A source code review of lha was conducted by the SuSE Security-Team
    to fix all possible buffer overflows.
    New packages are available at our FTP servers.

    - gfxboot/bootsplash-theme-SuSE/bootsplash-theme-SuSE-Home
    A bug in gfxboot on SUSE LINUX 9.1 caused the lilo boot password
    to be shown in cleartext while typing.
    The standard boot loader is grub.
    New packages are available at our FTP servers.

    - liby2util
    File names of patch files are no longer passed to gpg via the
    system() call. Since those file names are not protected by a digital
    signature, an attacker could previously manage to implant shell
    code.
    New packages are available at our FTP servers.

    - pure-ftpd
    This update fixes a possible DoS attack because of a bug in the
    accept_client function handling the setup of new connections.
    New packages are available at our FTP servers.

    - neon
    This update adds a missing filter for control characters.
    New packages are available at our FTP servers.

    - pavuk
    This update fixes several buffer overflows in pavuk's digest
    authentication support. Thanks to Matthew Murphy for reporting
    this issue to us.
    New packages are available at our FTP servers.

    - sox
    Several buffer overflows in the 'sox' and 'play' have been fixed that
    can be exploited by playing specially crafted .wav files. (CAN-2004-0557)
    New packages are available at our FTP servers.

    - gaim
    The SuSE Security Team discovers various remotely exploitable buffer
    overflows in the MSN-protocol parsing functions of gaim. The only
    affected product is SUSE LINUX 9.1.
    New packages will be available soon. (CAN-2004-0500)

    - kernel
    Paul Starzetz from iSEC informed us about a race condition in the 64bit
    file offset handling code of the kernel.
    New kernels for SUSE LINUX Enterprise Server 9 are available from
    the maintenance-web. The updates for the SUSE LINUX 9.1 kernels are
    available from our FTP servers.
    Kernel update packages for older SUSE LINUX distributions will be
    available in the next few days and will be announced with a dedicated
    advisory.

______________________________________________________________________________

6)  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 
       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 
       to verify the signature of the package, where  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.
       Prerequisites:
        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
    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-announce@suse.com
        -   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:
         or
         respectively.

    ====================================================================    SUSE's security contact is  or .
    The  public key is listed below.
    ====================================================================