______________________________________________________________________________

                        SuSE Security Announcement

        Package:                postfix
        Announcement-ID:        SuSE-SA:2003:033
        Date:                   Mon Aug  4 13:30:00 MEST 2003
        Affected products:      7.2, 7.3, 8.0, 8.1
                                SuSE Linux Database Server
                                SuSE eMail Server III, 3.1
                                SuSE Linux Enterprise Server 7, 8
                                SuSE Linux Connectivity Server
                                SuSE Linux Office Server
                                SuSE Linux Openexchange Server
                                UnitedLinux 1.0
                                SuSE Linux Desktop 1.0
        Vulnerability Type:     remote Denial of Service (DoS) attack
        Severity (1-10):        4
        SuSE default package:   Since SuSE Linux 8.1.
        Cross References:       CAN-2003-0468
                                CAN-2003-0540

    Content of this advisory:
        1) security vulnerability resolved: remote DoS in postfix
           problem description, discussion, solution and upgrade information
        2) pending vulnerabilities, solutions, workarounds:
            - kernel
        3) standard appendix (further information)

______________________________________________________________________________

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

    Postfix is a flexible MTA replacement for sendmail.
      Michal Zalewski has reported problems in postfix which can lead to
    a remote DoS attack or allow attackers to bounce-scan private networks.
    These problems have been fixed. Even though not all of our products are
    vulnerable in their default configurations, the updates should be applied.

    In order for the update to take effect, you have to restart your MTA
    by issuing the following command as root:

      "/sbin/rcpostfix restart"


    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.

    i386 Intel Platform:

    SuSE-8.1:
      
      4b3b65905911440051f869b3e95c2c66
    patch rpm(s):
      
      e73917624b5adfdbe113909135a50a42
    source rpm(s):
      
      0e5bcc6c3cd95f09c423cf00aac0c303

    SuSE-8.0:
      
      e0090e0ed051a532a62d787b020ac580
    patch rpm(s):
      
      8c156ca92ad4be83588041192efe5b60
    source rpm(s):
      
      f9389f00de109cea2f0b3b6c27f5a515

    SuSE-7.3:
      
      1f4d3af8d10850096bc0260567caa334
    source rpm(s):
      
      0ccc29a957609b3aeb2c12f3cc85284d

    SuSE-7.2:
      
      444f983a8c8f0d18621a1e8b4c3dd260
    source rpm(s):
      
      6d479bd0ed90bc7dc59a4201327ffc05


    Sparc Platform:

    SuSE-7.3:
      
      83eb074dbcedae2c9947006b4c0411d2
    source rpm(s):
      
      ec7ae58e31fd2ec63ccd881454372307


    PPC Power PC Platform:

    SuSE-7.3:
      
      f7b331c15b7bf705274afe2665e9e187
    source rpm(s):
      
      f2e5aa58e24599777a95dce715c3bcad

______________________________________________________________________________

2)  Pending vulnerabilities in SuSE Distributions and Workarounds:

    - kernel
    Various bugs inside the kernel have been reported recently. The most
    important ones are
      - NFSv3 remote DoS
      - netfilter DoS
      - /proc infoleak
      - race condition in the ELF loader
    These bugs are fixed. The new kernel packages will be approved as soon as
    the testing is finished.

______________________________________________________________________________

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 
       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   .


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