______________________________________________________________________________

                        SuSE Security Announcement

        Package:                bind, glibc
        Announcement-ID:        SuSE-SA:2002:026
        Date:                   Tue Jul 09 2002
        Affected products:      7.0, 7.1, 7.2, 7.3, 8.0
				SuSE Linux Enterprise Server for S/390,
				SuSE Linux Database Server,
				SuSE eMail Server III,
				SuSE Linux Enterprise Server,
				SuSE Linux Firewall on CD
        Vulnerability Type:     buffer overflow
        Severity (1-10):        3
        SuSE default package:   yes
	Cross References:	CERT CA-2002-19; CVE CAN-2002-0651

    Content of this advisory:
	1) security vulnerability resolved: buffer overflow in
	   dig, host, and nslookup utilities.
           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

    A vulnerability has been discovered in some resolver library
    functions. The affected code goes back to the resolver library
    shipped as part of BIND4; code derived from it has been included
    in later BIND releases as well as the GNU libc.

    The bug itself is a buffer overflow that can be triggered if a
    DNS server sends multiple CNAME records in a DNS response.

    This bug has been fixed for the gethostbyXXX class of functions
    in GNU libc in 1999. Unfortunately, there is similar code in the
    getnetbyXXX functions in recent glibc implementations, and
    the code is enabled by default. However, these functions are
    the code is enabled by default. However, these functions are
    used by very few applications only, such as ifconfig and ifuser,
    which makes exploits less likely.

    We will make updated glibc packages available as they have gone
    through our build system, but without separate announcements.

    Until glibc patches are available, we recommend that you disable
    DNS lookups of network names in nsswitch.conf. Simply replace the
    line containing the tag "networks:" with this line:

		networks: files

    In the unlikely event that you've configured any name to network
    mapping via DNS, make sure you copy this information to
    /etc/networks.

    The resolver bug is also present in the libbind library included
    in BIND. This library is used by utilities from the bindutil package.

    We are therefore providing security updates for bind8 that
    address this vulnerability. As communicated previously (1),
    the SuSE security team is not providing fixes for BIND4 anymore.

    The bind9 packages shipped by SuSE are not vulnerable.

    Please download the update package for your distribution and
    verify its integrity by the methods listed in section 3) of this
    announcement.

    Apply the updata packages (bindutil, bind8) package using

	rpm -Fvh bind*.rpm

    If you are running the BIND name server, you should restart the name
    server process by issuing

    	rcnamed restart

    Our maintenance customers are being notified individually. The
    packages are being offered to install from the maintenance web.

    References:
	(1)  SUSE – Open-Source-Lösungen für Enterprise Server und Cloud | SUSE
	(1)  SUSE – Open-Source-Lösungen für Enterprise Server und Cloud | SUSE


______________________________________________________________________________

2)  Pending vulnerabilities in SuSE Distributions and Workarounds:

  - There is a format string bug in the "nn" news reader that can
    be exploited by a malicious NNTP server to execute arbitrary
    commands within the client user's account. We will be releasing
    updated packages.

______________________________________________________________________________

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 uninstalled 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 toplevel 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 annoucements 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-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 cleartext 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>