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SuSE Linux Advisory: openssl

Jul 30, 2002, 21:52 (0 Talkback[s])


                        SuSE Security Announcement

        Package:                openssl
        Announcement-ID:        SuSE-SA:2002:027
        Date:                   Tuesday, Jul 30th 2002 19:00 MEST
        Affected products:      7.0, 7.1, 7.2, 7.3, 8.0
                                SuSE Linux Database Server,
                                SuSE eMail Server 3.1,
                                SuSE Linux Enterprise Server,
                                SuSE Linux Firewall on CD,
                                SuSE Linux Connectivity Server
                                SuSE Linux Office Server
        Vulnerability Type:     remote command execution
        Severity (1-10):        8
        SuSE default package:   yes
        Cross References:       CAN-2002-0656, CAN-2002-0657, CAN-2002-0655,
                                CERT Advisory CA-2002-23

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


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

    The openssl package provides encryption functions and is used by many
    applications on SuSE products.

    Several buffer overflows have been discovered in the OpenSSL library
    affecting the SSL implementation, as well as a signedness issue
    in the ASN.1 decoding routines.

    In the SSL library, various blobs of data passed from the client to
    the server or vice versa were being copied to local buffers without
    checking their size. At least one overflow in the SSLv2 server code can
    be exploited by an attacker to gain access to the account under which
    the SSL enabled service is running. The other overflows happen in the
    SSL client code.
    The impact of this bug depends on the service using SSL. When attacking
    the Apache HTTP server with mod_ssl enabled, the perpetrator could gain
    access to the account "wwwrun". Attacking other services, such as the
    OpenLDAP slapd server, could even give the attacker access to the system's
    root account.

    Temporary workarounds for affected services include to disable the ssl
    functionality where this is possible. For ssl-enabled webservers, it is
    possible to temporarily disable SSLv2: Edit /etc/httpd/httpd.conf and
    add the following line to the mod_ssl configuration group:

        SSLProtocols all -SSLv2

    This should be considered a temporary workaround only.

    Since the SSL client implementation is affected as well, and due to the
    potential impact of the ASN.1 signedness issues, we recommend that users
    who do not run SSL enabled services upgrade their openssl package as well.
    By consequence, we recommend all users to update their openssl 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.

    After performing the package update, all services using the openssl
    libraries must be restarted for the update to become effective.
    This can be done by rebooting the server or by individually restarting
    the services in question manually. To find out which services use the
    openssl libraries, use the command

        fuser -v /usr/lib/* /usr/lib/*

    The ASN1 parser vulnerability was discovered by Adi Stav and James Yonan
    We would like to express our gratitude to the openssl team for
    their work on the package and the fix for the vulnerability.

    Intel i386 Platform:

    source rpm(s):

    source rpm(s):

    source rpm(s):

    source rpm(s):

    source rpm(s):

    Sparc Platform:

    The packages for the Sparc platform are being built by the time of the
    writing of this announcement and will be published without any delay.

    AXP Alpha Platform:

    The packages for the Alpha platform are being built by the time of the
    writing of this announcement and will be published without any delay.

    PPC Power PC Platform:

    source rpm(s):

    source rpm(s):

    source rpm(s):


2)  Pending vulnerabilities in SuSE Distributions and Workarounds:

  - chfn/util-linux
    Linux distributors have published security announcements about password
    locking race conditions that lead to a local root vulnerability.
    SuSE products are not affected by this weakness because we use the
    user/group management utilities from the shadow package. These utilities
    are not affected.

  - mod_ssl
    An off-by-one buffer overflow in the mod_ssl apache module is subject to
    an upcoming SuSE Security announcement, following this announcement.
    The upcoming announcement also treats a temporary file handling problem
    that has been discovered by Markus Meissner and Sebastian Krahmer,
    SuSE Security.

  - libpng
    libpng is a library that provides functions for applications to handle
    PNG image files (Portable Network Graphics). An overflow vulnerability
    has been found in the libpng library that may make it possible for an
    attacker to run arbitrary code or to crash an application that uses
    the libpng library if the application in question opens a png image file.
    We are in the process of fixing this vulnerability.

  - wwwoffle (World Wide Web Offline Explorer)
    wwwoffle fails to handle negative Content-Length values correctly.
    It is believed that an attacker can exploit this bug to gain remote
    access to the system running wwwoffle.
    We are working on update packages against this problem.

  - mod_php4-4.2*
    Security vulnerabilities have been found in php versions 4.2.0 and 4.2.1.
    SuSE systems are not affected because these systems use older versions
    of the php package.

  - The SuSE Linux 6.4 distribution has been announced to be discontinued
    in June. We have now moved the update directories for all architectures
    to the discontinued directory on our ftp server to indicate that no more
    updates will be made for this distribution.


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,
       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 "" 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
        -   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:
        <> or
        <> respectively.

    SuSE's security contact is <> or <>.
    The <> 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 <>
pub  1024D/9C800ACA 2000-10-19 SuSE Package Signing Key <>
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  SuSE Linux AG - Security       Phone: //             you need vision!"
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