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

                        SuSE Security Announcement

        Package:                Live CD 9.1
        Announcement-ID:        SuSE-SA:2004:011
        Date:                   Thursday, May 6th 2004 22:30 MEST
        Affected products:      SUSE LINUX 9.1 Personal Edition Live CD
        Vulnerability Type:     remote root access
        Severity (1-10):        8
        SuSE default package:   yes
        Other affected systems: none

    Content of this advisory:
        1) security vulnerability resolved: Live CD 9.1
           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 freshly released SUSE LINUX 9.1 comes in two variants: 
    * SUSE LINUX 9.1 Professional (5 CD-ROMs, 2 double sided DVDs, printed
      manuals, for Intel i386 32Bit platform and 1 DVD for the AMD 64Bit
      platform)
    * SUSE LINUX 9.1 Personal (2 CD-ROMs: 1 installable CD-ROM, 1 Live CD-ROM
      for running SUSE LINUX on your PC without actually installing the
      system.)

    This SUSE Security Announcement targets the Live CD that comes with the
    SUSE LINUX 9.1 Personal edition. The Live CD can boot and run on any PC
    that has a CD-ROM drive, offering a convenient opportunity for users
    who want to try out SUSE Linux without any modification to the system
    that is installed on the computer. Similar CD-ROM iso images have been
    available for download from our ftp server with each release of the 
    SUSE LINUX home user product for years.
    Upon boot, the Live CD will automatically configure a network card if 
    one has been detected. It requires user interaction for dialup 
    network access.

    A configuration error on the Live CD allows for a passwordless, remote 
    root login to the system via ssh, if the computer has booted from the 
    Live CD and if it is connected to a network. Since the CD-ROM is a 
    read-only medium by definition, there is no solution for this error 
    that would be persistent over a reboot from the Live CD. Manually 
    killing all running instances of the secure shell daemon ("killall 
    sshd" as root) after each boot cures the problem, while still exposing 
    the vulnerability in the time window between startup and the killing 
    of the sshd process.

    It is a policy for a fresh install of SUSE LINUX products to enable 
    the user to log on to the system using secure shell (ssh). During the 
    installation of the system, the user is prompted for a root password.
    The Live CD does not install any system on a medium and therefore does 
    not ask for a root password. By consequence, passwordless logins 
    should be denied on the system, regardless of whether the account in 
    question is the super user account or not. The Live CD 9.1 suffers 
    from this misconfiguration.
    Our permanent fix for the vulnerability is to download the iso image 
    of the fixed Live CD 9.1 from the URL as listed below and to burn it 
    on a CD-R using a CD-burner and the software that comes with the SUSE 
    LINUX 9.1 Personal or Professional (cdrecord, k3b). The new image 
    still runs a secure shell daemon for remote login, but it does not 
    allow remote logins on a zero-length password account, and it denies
    remote root login attempts, independently from the password.

    We thank Patrick Kranefeld and Fabian Franz who have reported the 
    configuration neglectfulness on the SUSE LINUX 9.1 Live CD to SUSE 
    Security.

    Image authenticity verification:
    The file LiveCD-9.1-01.iso has a length of 706349056 bytes. If you run 
    the command "md5sum LiveCD-9.1-01.iso" after you have downloaded the 
    file, the md5sum command should print the following md5sum:

        9f4ed1bc6b3ee582bf593fde75d5db43

    This md5 sum is also contained in the file MD5SUMS in the same 
    directory as the LiveCD-9.1-01.iso file. Its signature (by 
    security@suse.de) is contained in the file MD5SUMS.sig.

    The download location:

          9f4ed1bc6b3ee582bf593fde75d5db43

    A note: Please use a mirror for downloading the SUSE LINUX 9.1 Live 
    CD. Mirrors close to you can be found at 
    https://www.suse.com/


______________________________________________________________________________

2)  Pending vulnerabilities in SuSE Distributions and Workarounds:

    - canna
    New canna packages are available on our ftp servers, fixing tmp race
    conditions.
    
    - xchat
    A buffer overflow in the SOCKS5 code of the XChat program has been
    fixed. New packages are available on our ftp servers.

    - tcpdump
    The tcpdump program contained a remote DoS condition in its ISAKMP
    packet handling (CAN-2004-0183 and CAN-2004-0184).
    Fixed packages are available on our ftp servers.

    - lha
    A buffer overflow in the header parsing routines of lha has been fixed.
    Additionally lha did not properly handle pathnames within archives
    (CAN-2004-0234 and CAN-2004-0235).
    Fixed 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 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 ftp://ftp.suse.com/pub/suse/pubring.gpg-build.suse.de .


  - 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-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
                .

    For general information or the frequently asked questions (faq) 
    send mail to:
         or
         respectively.

    ====================================================================    SuSE's security contact is  or .
    The  public key is listed below.
    ====================================================================