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                        SuSE Security Announcement

        Package:                modules
        Announcement-ID:        SuSE-SA:2000:44
        Date:                   Monday, November 13th, 2000 10:00 MEST
        Affected SuSE versions: 6.4, 7.0
        Vulnerability Type:     local root compromise
        Severity (1-10):        8
        SuSE default package:   yes
        Other affected systems: many newer Linux distributions

    Content of this advisory:
        1) security vulnerability resolved: modprobe shell metacharacter
                                            expansion
           problem description, discussion, solution and upgrade information
        2) pending vulnerabilities, solutions, workarounds
        3) standard appendix (further information)

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

    The modules package is responsible for on-demand loading of kernel 
    modules/drivers. The /sbin/modprobe command, when executed as a new
    task by the kernel-internal function request_module(), runs with the
    priviledges of the init process, usually root.
    Newer versions of the modprobe program contain a bug 
    which allows local users to gain root priviledges. modprobe expands 
    given arguments via /bin/echo and can easily be tricked into executing
    commands. In order for this bug to be exploitable, a setuid root program
    must be installed that can trigger the loading of modules (such as ping6).

    The fix for this bug consists of a change to modprobe which disables
    the expansion of arguments to modprobe via /bin/echo.

    A temporary workaround for this bug is to disable the automatic loading
    of modules in the running kernel by running the command (as root)

        /sbin/sysctl -w kernel.modprobe=/
    or
        echo "/" > /proc/sys/kernel/modprobe

    Please note that this temporary workaround will have to be repeated
    after the next reboot to become effective again.

    Download the update package from locations desribed below and install 
    the package with the command `rpm -Uhv file.rpm'. The md5sum for each
    file is in the line below. You can verify the integrity of the rpm
    files using the command
        `rpm --checksig --nogpg file.rpm',
    independently from the md5 signatures below.


    i386 Intel Platform:

    SuSE-7.0
      
      9643216a1e0c147635ef62d894a9d7ad 

    source rpm:
      
    Due to a packaging error, the modules package source rpm is not
    available on our ftp servers yet. It will appear at the location above
    in very few hours.


    SuSE-6.4
      
      d3a95b93e549aae9a462e84d179efe45 

    source rpm:
      
    Due to a packaging error, the modules package source rpm is not
    available on our ftp servers yet. It will appear at the location above
    in very few hours.


    Sparc Platform:

    SuSE-7.0
      
      c0ab9aab7a61cefdb2cade98c663d4e3 

    source rpm:
      
    Due to a packaging error, the modules package source rpm is not
    available on our ftp servers yet. It will appear at the location above
    in very few hours.


    AXP Alpha Platform:

    SuSE-6.4
      
      a88b84d7f3d79f2a47ff9e78681a0390 

    source rpm:
      
    Due to a packaging error, the modules package source rpm is not
    available on our ftp servers yet. It will appear at the location above
    in very few hours.


    PPC Power PC Platform:

    SuSE-7.0:
      
      ef09b5c6438a0de8e18653e0a60d9c4c
 
    source rpm:
      
    Due to a packaging error, the modules package source rpm is not
    available on our ftp servers yet. It will appear at the location above
    in very few hours.

    SuSE-6.4
      
      27ba13500292c44969dd865f0c543c19 

    source rpm:
      
    Due to a packaging error, the modules package source rpm is not
    available on our ftp servers yet. It will appear at the location above
    in very few hours.


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2)  Pending vulnerabilities in SuSE Distributions and Workarounds:

    A seperate message is being prepared to address the currently ongoing
    security vulnerabilites.    
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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 
                <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>.
    ==============================================
Regards,
Sebastian Krahmer 

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