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SuSE Linux Advisory: wwwoffle

Aug 02, 2002, 03:20 (1 Talkback[s])


                        SuSE Security Announcement

        Package:                wwwoffle
        Announcement-ID:        SuSE-SA:2002:029
        Date:                   Thursday, Aug 1st 2002 12:30 MEST
        Affected products:      7.1, 7.2, 7.3, 8.0
        Vulnerability Type:     remote privilege escalation
        Severity (1-10):        4
        SuSE default package:   no
        Other affected systems: all systems using wwwoffle

    Content of this advisory:
        1) security vulnerability resolved: insufficient checking of
                                            Content Length value
           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 WWWOFFLE, World Wide Web Offline Explorer, program suite acts as a
    HTTP, FTP and Finger proxy to allow users with dial-up access to the
    internet to do offline WWW browsing.

    The parsing code of wwwoffled that processes HTTP PUT and POST requests
    fails to handle a Content Length value smaller then -1. It is believed
    that an attacker could exploit this bug to gain remote wwwrun access
    to the system wwwoffled is running on.

    The wwwoffle package is not installed by default.
    As temporary workaround the wwwoffle daemon can be disabled the following
    way (as root):
        rcwwwoffle stop
    If wwwoffled is started at boottime, you have to modify your boot
    scripts too. This can be done by using the runlevel editor of yast2.

    All running instances of wwwoffled need to be restarted after updating
    your system (as root):
        rcwwwoffle 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.

    Missing packages will be published as soon as possible.

    i386 Intel Platform:

    source rpm:

    source rpm:

    source rpm:

    source rpm:

    Sparc Platform:

    source rpm:

    AXP Alpha Platform:

    source rpm:

    PPC Power PC Platform:

    source rpm:

    source rpm:


2)  Pending vulnerabilities in SuSE Distributions and Workarounds:

  - bzip
    The FreeBSD Team discovered some security related bugs in bzip2.
    By exploiting this bugs an attacker could change file permissions or
    overwrite files.
    Bzip got fixed and a new version of the bzip package is available
    on our FTP servers.

  - pam_ldap
    A "format string" bug in pam_ldap's logging functions gots fixed.
    New packages are available on our FTP servers.

  - 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.

  - 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.


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>

  Thomas Biege <thomas@suse.de>
  SuSE Linux AG,Deutschherrnstr. 15-19,90429 Nuernberg
  Function: Security Support & Auditing
  "lynx -source http://www.suse.de/~thomas/contact/thomas.asc | pgp -fka"
  Key fingerprint = 51 AD B9 C7 34 FC F2 54  01 4A 1C D4 66 64 09 83
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