______________________________________________________________________________

                        SuSE Security Announcement

        Package:                glibc
        Announcement-ID:        SuSE-SA:2003:027
        Date:                   Monday, May 26th 2003 16:12 MET
        Affected products:      7.1, 7.2, 7.3, 8.0, 8.1
                                SuSE Linux Database Server,
                                SuSE eMail Server III, 3.1
                                SuSE Linux Enterprise Server 7,
                                SuSE Linux Firewall on CD/Admin host
                                SuSE Linux Connectivity Server
                                SuSE Linux Office Server
        Vulnerability Type:     remote system compromise
        Severity (1-10):        6
        SuSE default package:   yes
        Cross References:       CAN-2003-0028

    Content of this advisory:
        1) security vulnerability resolved: integer overflow in XDR code
           problem description, discussion, solution and upgrade information
        2) pending vulnerabilities, solutions, workarounds:
            - ethereal
            - XFree4
            - vnc
            - bitchx
            - lv
        3) standard appendix (further information)

______________________________________________________________________________

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

    Another integer overflow was found in glibc' XDR code. This bug is equal
    to the one described in advisory SuSE-SA:2002:031. The overflow occurs in
    the function xdrmem_getbytes() and can be used by external attackers to
    execute arbitrary code.

    There is no temporary workaround for this security problem other than
    disabling all RPC based server and client programs. The permanent
    solution is to update the glibc packages with the update packages
    listed below.


    Notes, Special installation instructions:

      * PRECAUTIONS
        The shared libraries package of the glibc is the most sensitive
        part of a running Linux system, and modifications to it should be
        handled with special care. During the update of the shlibs/glibc
        package, runtime-linking the shared libraries is likely to fail for
        processes that execute a new binary with the execve(2) system call.
        Therefore, we recommend to bring a system to single user mode
        ("init S") to perform the package update. If this is not applicable
        for operational reasons, a system receiving the update should be kept
        as quiet as possible (no shell scripts of any kind, no cron jobs, no
        incoming email).

      * After performing the update, you should run the following command
        on your system:
            /sbin/ldconfig
        ldconfig will rebuild the runtime linker cache. If you use YOU
        (Yast2 Online Update), the ldconfig command will be executed
        automatically at the end of the update.

        The shared libraries that were installed on the system before the
        update have been removed from the filesystem, but they are still
        in use by the running applications. Therefore, the disk-space as well
        as the memory will not be freed until the last process that uses
        these files exits. We recommend to reboot the system to workaround
        this problem.


    Listed below you find the URLs for the update packages for the SuSE Linux
    products. We only list the packages that are relevant for the security update.
    Our maintenance customers are being notified individually. The packages
    are being offered to install from the maintenance web.


    Intel i386 Platform:

    SuSE-8.1:
      
      1cf549fa52427710c7dc3316fc5df4a6
    patch rpm(s):
      
      f87601fd71edf54928104581684dae8f

    SuSE-8.0:
      
      da51402d30c37dd5dc6d5444c37f4dc3
    patch rpm(s):
      
      0b5ea57d89c31d923cfb56cb1f951bac
    source rpm(s):
      
      6fecec2ed42fb792b6e9cb2a5602fe23

    SuSE-7.3:
      
      11cc1ceb173b18fc82d8500b1528663e
    source rpm(s):
      
      38527e5f75d94c016659c71028c37c52

    SuSE-7.2:
      
      82f4c3ee8ba0cf3feef5e0ba7321a230
    source rpm(s):
      
      34114134cb51d706989c45306f4fdde3

    SuSE-7.1:
      
      ffe7c422727ee98b8191facbbf40b9d7
    source rpm(s):
      
      1c5b778ff60a82f03e412239b907671b



    Sparc Platform:

    SuSE-7.3:
      
      dc577491e13344411462603b6fe83d3f
    source rpm(s):
      
      0a0a5dd6ee76e6b0ef866b500d6537b2



    AXP Alpha Platform:

    SuSE-7.1:
      
      d250c254668e02b9f23341903f2f3a5e
    source rpm(s):
      
      d89b4a1ff27227a085e516b48ccdb1cf



    PPC Power PC Platform:

    SuSE-7.3:
      
      5bf4edf432c996b3e38ef085122e1e8

______________________________________________________________________________

2)  Pending vulnerabilities in SuSE Distributions and Workarounds:

    - ethereal
      Several one-byte buffer overflows and integer overflows are fixed.
      These bugs lead to remote denial-of-service or even remote code
      execution.
      New packages are available on our FTP servers.

    - XFree4
      A buffer overflow in the Xlib code can be triggered while handling
      the environment variable XLOCALEDIR. The X version affected is 4.2.0
      (SuSE Linux 8.0 and 8.1).
      New packages are available on our FTP servers.

    - vnc
      VNC (Virtual Network Computing) uses a weak cookie generation process
      which can be exploited by an attacker to bypass authentication.
      New packages are available on our FTP servers.

    - bitchx
      Several buffer overflows got fixed that can be exploited remotely by
      a malicious IRC servers.
      New packages are available on our FTP servers.

    - lv
      lv reads config files from the current directory without verifying the
      ownership. If lv is called in world-writeable directories like /tmp it
      can be tricked into executing commands by putting a malicious config-
      file there.
      New packages are available on our FTP servers.

______________________________________________________________________________

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>