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From: Roman Drahtmueller (draht_at_suse.de)
Date: Mon Mar 03 2003 - 13:19:51 CST

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                            SuSE Security Announcement

            Package: sendmail, sendmail-tls
            Announcement-ID: SuSE-SA:2003:013
            Date: Monday, March 3rd 2003, 18:10 MET
            Affected products: 7.1, 7.2, 7.3, 8.0, 8.1
                                    SuSE Linux Database Server,
                                    SuSE Linux Enterprise Server 7, 8
                                    SuSE Linux Firewall on CD/Admin host
                                    SuSE Linux Connectivity Server
                                    SuSE Linux Office Server
            Vulnerability Type: local privilege escalation
            Severity (1-10): 7
            SuSE default package: yes (until SuSE Linux 8.0 and SLES7)
            Cross References: http://www.cert.org/advisories/CA-2003-07.html

        Content of this advisory:
            1) security vulnerability resolved: sendmail
               problem description, discussion, solution and upgrade information
            2) pending vulnerabilities, solutions, workarounds:
                - vnc
                - w3m
            3) standard appendix (further information)


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

        sendmail is the most widely used mail transport agent (MTA) in the
        internet. A remotely exploitable buffer overflow has been found in all
        versions of sendmail that come with SuSE products. These versions include
        sendmail-8.11 and sendmail-8.12 releases. sendmail is the MTA subsystem
        that is installed by default on all SuSE products up to and including
        SuSE Linux 8.0 and the SuSE Linux Enterprise Server 7.

        The vulnerability is triggered by an email message sent through the
        sendmail MTA subsystem. In that respect, it is different from commonly
        known bugs that occur in the context of an open TCP connection. By
        consequence, the vulnerability also exists if email messages get forwarded
        over a relay that itself does not run a vulnerable MTA. This specific
        detail and the wide distribution of sendmail in the internet causes this
        vulnerability to be considered an error of major severity.

        The buffer overflow happens on the heap and is known to be exploitable.
        As of the writing of this announcement, there is no exploit known to exist
        in the public. Since there is no known workaround for this vulnerability
        other than using a different MTA, it is strongly recommended to install
        the update packages as offered at the locations as listed below.

        We would like to express our gratitude to Eric Allman for notifying
        SuSE Security of the problem. The vulnerability was discovered by
        ISS Internet Security Systems, inc.

        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.

        After performing the update, it is necessary to restart all running
        instances of sendmail using the command "rcsendmail restart" as root.

        Intel i386 Platform:

        patch rpm(s):
        source rpm(s):

        patch rpm(s):
        source rpm(s):

        source rpm(s):

        source rpm(s):

        source rpm(s):

        Sparc Platform:

        source rpm(s):

        AXP Alpha Platform:

        source rpm(s):

        PPC Power PC Platform:

        source rpm(s):

        source rpm(s):


    2) Pending vulnerabilities in SuSE Distributions and Workarounds:

      - vnc
        VNC (Virtual Network Computing) uses a weak cookie generation process
        which can be exploited by an attacker to bypass authentication.
        New packages are currently being tested and will be available on our
        FTP servers soon.

      - w3m
        The textbased web-browser w3m does not properly escape HTML tags.
        A malicious HTML page or img alt attribute may lead to information
        leakage. New packages will be available soon.

    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 securitysuse.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 "buildsuse.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-infosuse.com> or
            <suse-security-faqsuse.com> respectively.

        SuSE's security contact is <securitysuse.com> or <securitysuse.de>.
        The <securitysuse.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 <securitysuse.de>
    pub 1024D/9C800ACA 2000-10-19 SuSE Package Signing Key <buildsuse.de>

    Version: GnuPG v1.0.6 (GNU/Linux)
    Comment: For info see http://www.gnupg.org