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SuSE Security Announcement: openssh/ssh

Nov 26, 2000, 17:48 (0 Talkback[s])
Date: Fri, 24 Nov 2000 16:51:38 +0100 (MET)
From: Roman Drahtmueller draht@suse.de
To: suse-security-announce@suse.de
Subject: [suse-security-announce] SuSE Security Announcement: openssh/ssh
    (SuSE-SA:2000:47)

______________________________________________________________________________

                        SuSE Security Announcement

        Package:                openssh/ssh
        Announcement-ID:        SuSE-SA:2000:47
        Date:                   Friday, November 24th, 2000 16:30 MET
        Affected SuSE versions: 6.4, 7.0
        Vulnerability Type:     clientside remote vulnerability
        Severity (1-10):        6
        SuSE default package:   yes
        Other affected systems: systems w/ openssh versions before 2.3.0

    Content of this advisory:
        1) security vulnerability resolved: openssh
           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

    openssh is an implementation of the secure shell protocol, available under
    the BSD license, primarily maintained by the OpenBSD Project.

    Many vulnerabilities have been found in the openssh package, along with
    a compilation problem in the openssh and ssh packages in the SuSE-7.0 
    distribution: An openssh client (the ssh program) can accept X11- or
    ssh-agent forwarding requests even though these forwarding capabilities
    have not been requested by the client side after successful authentication.
    Using these weaknesses, an attacker could gain access to the 
    authentication agent which may hold multiple user-owned authentification
    identities, or to the X-server on the client side as if requested by the
    user. These problems have been found/reported by Markus Friedl 
    and Jacob Langseth.

    A problem in the configure script in both the openssh and ssh package
    on the SuSE-7.0 distribution caused the sshd programs to not be linked
    against the tcp-wrapper library. By consequence, access rules for the sshd
    server-side service as configured in /etc/hosts.allow and /etc/hosts.deny
    were ignored. This has been reported to us by Lutz Pressle.
    We thank these individuals for their contribution.
    Sebastian Krahmer found a small tmp file handling
    problem in the perl script `make-ssh-known-hosts. A (local) attacker
    could trick the perl program to follow symbolic links and thereby 
    overwriting files with the privileges of the user calling 
    make-ssh-known-hosts.

    The solution for the first three problems (agent+X11-forwarding, missing
    libwrap support) is an upgrade to a newer package. The tmp file problem 
    can be easily solved by hand. Please see the special install instructions
    below.

    Note: Upon public request, we also provide update packages for the 
          SuSE-6.3 Intel distribution, even though the openssh packages
          was not included in this distribution.


    special install instructions:
    =====================================

    To find out which package (ssh or openssh) you use, please use the command
    `rpm -qf /usr/bin/ssh.
    __
    case openssh: 
        Please follow the instructions below to download and install
        the update package. Afterwards, restart the sshd daemon:
               `rcsshd restart.
    __
    case ssh:
      before SuSE-7.0 (excluding 7.0):
          In the file /usr/bin/make-ssh-known-hosts, please change the line
          (around line 102)

            $private_ssh_known_hosts = "/tmp/ssh_known_hosts$$";
          to read
            $private_ssh_known_hosts = "~/ssh_known_hosts$$";
          and you are done. 

      SuSE-7.0: Please follow the instructions below to download
          and install the update package. Afterwards, restart the sshd daemon:
                `rcsshd restart    


    Please choose the update package(s) for your distribution from the URLs
    listed below and download the necessary rpm files. Then, install the
    package using the command `rpm -Uhv file.rpm. rpm packages have an 
    internal md5 checksum that protects against file corruption. You can
    verify this checksum using the command (independently from the md5 
    signatures below)
        `rpm --checksig --nogpg file.rpm',
    The md5 sums under each package are to prove the package authenticity,
    independently from the md5 checksums in the rpm package format.


    i386 Intel Platform:

    SuSE-7.0
    ftp://ftp.suse.de/pub/suse/i386/update/7.0/sec1/openssh-2.3.0p1-0.i386.rpm
      3c7b9044ffb64f9f74c904eb2b278eb2
    source rpm:
    ftp://ftp.suse.de/pub/suse/i386/update/7.0/zq1/openssh-2.3.0p1-0.src.rpm
      aebcda19518208497671e752bbdfaeb8

    SuSE-6.4
    ftp://ftp.suse.de/pub/suse/i386/update/6.4/sec1/openssh-2.3.0p1-0.i386.rpm
      04c17b0eba99c798ae401fb9aafbc7e4
    source rpm:
    ftp://ftp.suse.de/pub/suse/i386/update/6.4/zq1/openssh-2.3.0p1-0.src.rpm
      2003ab41cfa32ef39b11b4977ef4cd1f

    SuSE-6.3
    ftp://ftp.suse.de/pub/suse/i386/update/6.3/sec1/openssh-2.3.0p1-0.i386.rpm
      04c17b0eba99c798ae401fb9aafbc7e4
    source rpm:
    ftp://ftp.suse.de/pub/suse/i386/update/6.3/zq1/openssh-2.3.0p1-0.src.rpm
      2003ab41cfa32ef39b11b4977ef4cd1f


    Sparc Platform:

    SuSE-7.0
    ftp://ftp.suse.de/pub/suse/sparc/update/7.0/sec1/openssh-2.3.0p1-0.sparc.rpm
      898aaaacee88777429496f1a5658076f
    source rpm:
    ftp://ftp.suse.de/pub/suse/sparc/update/7.0/zq1/openssh-2.3.0p1-0.src.rpm
      97868b04de04a0baafcee69ebbbe6079


    AXP Alpha Platform:

    SuSE-7.0
    ftp://ftp.suse.de/pub/suse/axp/update/7.0/sec1/openssh-2.3.0p1-0.alpha.rpm
      dd12c60b2744455780c976b115b26f27
    source rpm:
    ftp://ftp.suse.de/pub/suse/axp/update/7.0/zq1/openssh-2.3.0p1-0.src.rpm
      6df5af1a88fda4d8fc1a493e4d10bc01

    SuSE-6.4
    ftp://ftp.suse.de/pub/suse/axp/update/6.4/sec1/openssh-2.3.0p1-0.alpha.rpm
      99de4bb6f183be1b69a610744f4566bc
    source rpm:
    ftp://ftp.suse.de/pub/suse/axp/update/6.4/zq1/openssh-2.3.0p1-0.src.rpm
      aa56e311205ba58478c815760452367e


    PPC Power PC Platform:

    SuSE-7.0
    ftp://ftp.suse.de/pub/suse/ppc/update/7.0/sec1/openssh-2.3.0p1-0.ppc.rpm
      72f7c339991e54a476585012423dda62
    source rpm:
    ftp://ftp.suse.de/pub/suse/ppc/update/7.0/zq1/openssh-2.3.0p1-0.src.rpm
      749ccc55396944ad43c1977e55903958

    SuSE-6.4
    ftp://ftp.suse.de/pub/suse/ppc/update/6.4/sec1/openssh-2.3.0p1-0.ppc.rpm
      59727fa055e5d835bc4e455302b1ef49
    source rpm:
    ftp://ftp.suse.de/pub/suse/ppc/update/6.4/zq1/openssh-2.3.0p1-0.src.rpm
      7e42dbad4e50a2ad9156e94cf2a93955

______________________________________________________________________________

2)  Pending vulnerabilities in SuSE Distributions and Workarounds:

    Clarification:
    In my message (Subject: "SuSE: miscellaneous"), dated Wed, 15 Nov 2000,
    concerning the paragraph about runtime linking problems in gs 
    (GhostScript) , I have stated that the problem will be fixed in future
    versions of the SuSE distribution. This does not touch the fact that we
    will of course provide fixes for the older distributions.


    - pine

      The packages (version 4.30) are on our ftp server and can be downloaded.
      The SuSE security announcement is pending.


    - netscape

      Michal Zalewski has reported a buffer overflow
      in Netscape's html parser code. A specially crafted html document may
      cause the browser to execute arbitrary code as the user calling the
      netscape program. The packages are available for download on ftp.suse.com.
      A security announcement is on the way to address the issue.

    - gs (ghostscript)

      Two vulnerabilities have been found in the ghostscript package as shipped
      with SuSE distributions: Insecure temporary file handling and a linker
      problem that could make gs runtime-link against ./libc.so.6.
      We're currently working on update packages. In the meanwhile, it is 
      advised to not run gs or applications that call gs from within a world-
      writeable directory.


    - jed

      The text editor jed saves files in /tmp upon emergency termination in an
      insecure way. This problem was fixed with the release of SuSE-6.3 after
      a SuSE-internal code audit by Thomas Biege thomas@suse.de. The 
      information about the existence of this bug was not communicated to the
      public because the editor was not very widely used at that time.
      We will provide update packages for the SuSE releases 6.0, 6.1 and 6.2
      shortly.
______________________________________________________________________________

3)  standard appendix:

    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 
                mailto: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's security contact is security@suse.com.
    ===============================================