______________________________________________________________________________

                        SuSE Security Announcement

        Package:                bind8
        Announcement-ID:        SuSE-SA:2002:044
        Date:                   Wed Nov 13 17:00:00 CET 2002
        Affected products:      (7.0), 7.1, 7.2, 7.3, 8.0, 8.1,
                                SuSE Linux Database Server
                                SuSE eMail Server III, 3.1
                                SuSE Firewall
                                SuSE Linux Enterprise Server for S/390
                                SuSE Linux Connectivity Server
                                SuSE Linux Enterprise Server 7
                                SuSE Linux Office Server
        Vulnerability Type:     remote command execution
        Severity (1-10):        8
        SuSE default package:   yes
        Cross References:       CVE CAN-2002-1219,
                                CAN-2002-1220, CAN-2002-1221,
                                  
                                  

    Content of this advisory:
        1) security vulnerability resolved: Remote command execution
           in bind8 name server.
           problem description, discussion, solution and upgrade information
        2) pending vulnerabilities, solutions, workarounds: BIND4, reports
           of trojanized tcpdump/libpcap
        3) standard appendix (further information)

______________________________________________________________________________

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

    The security research company ISS (Internet Security Services)
    has discovered several vulnerabilities in the BIND8 name server,
    including a remotely exploitable buffer overflow.
    Circumstancial evidence suggests that the Internet Software
    Consortium (maintainer of BIND) has been made aware of these issues
    in mid-October. Distributors of Open Source operating systems,
    including SuSE, were notified of these vulnerabilities via CERT
    approximately 12 hours before the release of the advisories by ISS
    and ISC on Tue, Nov 12. This notification did not include any details
    that allowed us to identify the vulnerable code, much less prepare
    a fix. Mails to ISC went unanswered for 36 hours.

    The SuSE security team regrets that the Internet Software Consortium
    has withheld vital information from the Internet community for so long,
    putting the majority of BIND users at risk. We would like to express
    our concern that the approach chosen by ISC and ISS is likely to
    erode trust in the security community if it becomes a model for dealing
    with security issues.

    We apologize to SuSE customers for not being able to provide timely
    fixes for this problem.

    The advisories by ISS and ISC mention the following problems
    in detail:

     1. There is a buffer overflow in the way named handles
        SIG records. This buffer overflow can be exploited to
        obtain access to the victim host under the account
        the named process is running with.

        In order to exploit this problem, the attacker must
        control an existing DNS domain, and must be allowed
        to perform a recursive query.

        The impact of this vulnerability is serious.

        In all SuSE products, named is configured to run as user "named"
        by default, so a potential attacker or virus/worm does not get
        immediate root access. However, this is merely an additional
        obstacle the attacker faces. It may be possible for the attacker
        to exploit other, unpatched local vulnerabilities such as the
        recently announced traceroute hole to obtain root privilege. It
        may also be possible for an attacker to obtain increased privilege
        by manipulating the DNS zones served by the victim BIND server.
        We recommend to upgrade to the provided packages. If this is
        not possible, we recommend to restrict recursive requests as a
        workaround. This can be done by adding a statement such as the
        following to /etc/named.conf:

        options {
                ... existing options ...

                # Restrict recursive queries to 192.168.1.*,
                # except 192.168.1.254.
                # Order does matter.
                allow-recursion {
                        !192.168.1.254;
                        192.168.1/24;
                };
        };

        Alternatively, you can add "recursion no;" to the options
        section to turn off recursion completely.

     2. There are several Denial Of Service problems in BIND8
        that allow remote attackers to terminate the name server
        process.

        At least one of these vulnerabilities seems to be exploitable
        even when the attacker is not allowed to perform recursive
        queries, so that the workaround suggested above is not
        effective against this bug.

    Both vulnerabilities are addressed by this update, using patches
    originating from ISC.

    Due to the severity of this issue, we will provide update packages
    for SuSE Linux 7.0, even though support for this product has officially
    been discontinued.

    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 packages using the command "rpm -Fhv file.rpm" to apply
    the update. After updating, make sure to restart the name server
    process by issuing the following command as root:

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




    Intel i386 Platform:

    SuSE-8.1:
      
      e1c07d8c1dd74374cc37e7fa692c9de1
      
      b41734970bf88aa7b5d3debbf834b78d
      
      f7236e5e621725e100dbd204e2692a66
    source rpm(s):
      
      02154fbdc935a2900d70ce6a16e96543

    SuSE-8.0:
      
      07bc10c5c348c560084edb3c289459c9
      
      4db27e9ad4ae038d81422a0c5b9a34d0
      
      a1b3958e0fbaed30ddecbf7753007dbf
    source rpm(s):
      
      0b66ae2b5c462f041625919fed7ab089

    SuSE-7.3:
      
      fe0654b3de751533874b08a860afea5e
      
      043a8c1c0bb2cc23308a614dc7bdc0fe
      
      59aca78f5aacb3ff7ecbc252eb760956
    source rpm(s):
      
      355add6397435262c597ad662e3df119

    SuSE-7.2:
      
      1072a9fe708150bc14c70a72ca42dfd3
      
      0713d9b200db862110493233bc1d8321
      
      c681a91b38104cf47de4f4d454136a8a
    source rpm(s):
      
      8f51737bc0c84b7be08fe3bb1d4012b4

    SuSE-7.1:
      
      f2c14f81038d7ba952def27981b4599c
      
      961a5403a41e8031c054a081ebf92ba5
    source rpm(s):
      
      7f3c9b95591fb22f00dc0b22cdd5fcf1

    SuSE-7.0:
      
      0a6b9e23cefa5cd9f06660571ebf85ff
      
      3a6e0e81c2d8b05ee01a2a0b9c26e9a4
    source rpm(s):
      
      1c2cb2e531fe2834de84b22ad714de68



    Sparc Platform:

    SuSE-7.3:
      
      c08454b933ed2365d9d2ab1322803af6
      
      47e063be85fadfa2e5d0fce1746a34b5
      
      46a97b033cca0a01dcb39ef90275ce46
    source rpm(s):
      
      827a7f56273c7a25ac40ffba728e9150


    AXP Alpha Platform:

    SuSE-7.1:
      
      77f39990fabacb545657236a60fecbe0
      
      33bf9f28a7c9105c84216906694c7b7c
    source rpm(s):
      
      df347649fc98de695837a88452814ee6

    SuSE-7.0:
      
      23f307cda6a0eefb3d9f1a0439950bdd
      
      0789b49749d93ddd79192506cda00f7a
    source rpm(s):
      
      356306a7f2c079e2726b3aa8da496e9b



    PPC Power PC Platform:

    SuSE-7.3:
      
      4cbeb4719625f8735ec03c27e1b27b85
      
      37fca302d72c819e713f8038d730a527
      
      f0f5cb7b808789606448a4d472c71400
    source rpm(s):
      
      5c810e6f144d0f2875bb06d2331f50d8

    SuSE-7.1:
      
      47fcc451954f03a915b57b500bd56c57
      
      2c0de3b64d5c3d62cb840a534911ef31
    source rpm(s):
      
      235e142413ec35bcbdb86168b04b7a78

    SuSE-7.0:
      
      44dc01f6b4fae1dfd87874db6d42e8d9
      
      d46f45bef0f12c3c5b071443ac9e7f13
    source rpm(s):
      
      1bac32496ae66d4b0e35bc34d4e500ff

______________________________________________________________________________

2)  Pending vulnerabilities in SuSE Distributions and Workarounds:

    BIND4
        In addition to the vulnerabilities in BIND8 discussed above, ISS
        report several vulnerabilities in BIND4. As stated previously,
        SuSE has discontinued support for BIND4 and recommends that
        users upgrade to BIND8 as soon as possible.

    Trojaned libpcap/tcpdump
        There have been reports that the source packages of tcpdump and
        libpcap available from several FTP servers have been modified to
        include a trojan. We have checked our source packages for this
        and found them to be clean.

______________________________________________________________________________

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 un-installed 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 top-level 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 announcements 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'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>