OSEC

Neohapsis is currently accepting applications for employment. For more information, please visit our website www.neohapsis.com or email hr@neohapsis.com
 
From: Rain Forest Puppy (rfpvulnwatch.org)
Date: Wed Jul 18 2001 - 13:21:03 CDT

  • Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

    Two things:

    1. This is a new, different vuln than the tcpdump AFS parsing overflow
    found a few months back (or so the advisory indicates). Since it's not a
    FreeBSD-specific problem, it's defintely worthy of alerting everyone.

    2. Pine's (please withhold groans) handling of whitespace may break the
    PGP singature; if you want to check it, snag a copy from one of the many
    FreeBSD advisory archives on the 'net.

    - rfp

    --------------------------------------------------------

    From: FreeBSD Security Advisories (security-advisoriesFreeBSD.org)
    Subject: FreeBSD Security Advisory FreeBSD-SA-01:48.tcpdump

    -----BEGIN PGP SIGNED MESSAGE-----

    =============================================================================
    FreeBSD-SA-01:48 Security Advisory
                                                                    FreeBSD, Inc.

    Topic: tcpdump contains remote buffer overflow

    Category: core
    Module: tcpdump
    Announced: 2001-07-17
    Credits: Nick Cleaton <nickcleaton.net>
    Affects: All releases of FreeBSD 4.x prior to 4.4,
                    FreeBSD 4.3-STABLE prior to the correction date
                    FreeBSD 3.x is unaffected.
    Corrected: 2001-07-09
    Vendor status: Patch released
    FreeBSD only: NO

    I. Background

    tcpdump is a tool for monitoring network traffic activity.

    II. Problem Description

    An overflowable buffer was found in the version of tcpdump included
    with FreeBSD 4.x. Due to incorrect string length handling in the
    decoding of AFS RPC packets, a remote user may be able to overflow a
    buffer causing the local tcpdump process to crash. In addition, it
    may be possible to execute arbitrary code with the privileges of the
    user running tcpdump, often root.

    The effects of this vulnerability are similiar to those described in
    advisory FreeBSD-SA-00:61.tcpdump.v1.1.

    All released versions of FreeBSD prior to the correction date
    including 4.3-RELEASE are vulnerable to this problem, however it does
    not affect the FreeBSD 3.x branch which includes an older version of
    tcpdump.

    III. Impact

    Remote users can cause the local tcpdump process to crash, and may be
    able to cause arbitrary code to be executed as the user running
    tcpdump, often root.

    IV. Workaround

    Do not use vulnerable versions of tcpdump in network environments
    which may contain packets from untrusted sources.

    V. Solution

    One of the following:

    1) Upgrade your vulnerable FreeBSD system to 4.3-STABLE or the
    RELENG_4_3 security branch after the respective correction dates.

    2) FreeBSD 4.x systems prior to the correction date:

    Download the patch and the detached PGP signature from the following
    locations, and verify the signature using your PGP utility.

    ftp://ftp.freebsd.org/pub/FreeBSD/CERT/patches/SA-01:48/tcpdump-4.x.patch
    ftp://ftp.freebsd.org/pub/FreeBSD/CERT/patches/SA-01:48/tcpdump-4.x.patch.asc

    # cd /usr/src/contrib/tcpdump
    # patch -p < /path/to/patch
    # cd /usr/src/usr.sbin/tcpdump
    # make depend && make all install

    3) FreeBSD 4.3-RELEASE systems:

    An experimental upgrade package is available for users who wish to
    provide testing and feedback on the binary upgrade process. This
    package may be installed on FreeBSD 4.3-RELEASE systems only, and is
    intended for use on systems for which source patching is not practical
    or convenient.

    If you use the upgrade package, feedback (positive or negative) is
    requested to security-officerFreeBSD.org so we can improve the
    process for future advisories.

    During the installation procedure, backup copies are made of the files
    which are replaced by the package. These backup copies will be
    reinstalled if the package is removed, reverting the system to a
    pre-patched state.

    Two versions of the upgrade package are available, depending on
    whether or not the system has openssl installed. To verify whether
    your system has openssl installed, perform the following command:

    # ls /usr/bin/openssl

    Possible responses:

    /usr/bin/openssl # This response indicates you have openssl present

    ls: /usr/bin/openssl: No such file or directory
                           # This reponse indicates you do not have
                           # openssl present

    3a) If OpenSSL is not present

    # fetch
    ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/packages/SA-01:48/security-patch-tcpdump-nossl-01.48.tgz
    # fetch
    ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/packages/SA-01:48/security-patch-tcpdump-nossl-01.48.tgz.asc

    Verify the detached PGP signature using your PGP utility.

    # pkg_add security-patch-tcpdump-nossl-01.48.tgz

    3b) If OpenSSL is present

    # fetch
    ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/packages/SA-01:48/security-patch-tcpdump-ssl-01.48.tgz
    # fetch
    ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/packages/SA-01:48/security-patch-tcpdump-ssl-01.48.tgz.asc

    Verify the detached PGP signature using your PGP utility.

    # pkg_add security-patch-tcpdump-ssl-01.48.tgz

    -----BEGIN PGP SIGNATURE-----
    Version: GnuPG v1.0.6 (FreeBSD)
    Comment: For info see http://www.gnupg.org

    iQCVAwUBO1R5i1UuHi5z0oilAQFdCQQAhFUzYA7plZN1O0rK/iU/jPaoCqM0KDPP
    Vdg+3zP8I5Vovdbxdns1DVefI3PVhZbLwh8E0ZnEz544FB5atiYsRiqQxuoEMZiN
    1JSRHUOIYyAChtIUZY1JV9eF8GfemWaAcgNp7mNWYKl7dUn0nYERfTO92YNm+l7M
    3nNvOwkhqLU=
    =PrXC
    -----END PGP SIGNATURE-----

    To Unsubscribe: send mail to majordomoFreeBSD.org
    with "unsubscribe freebsd-security" in the body of the message