SuSE alert: modules

Posted by dave on Nov 13, 2000 12:09 AM EDT
Mailing list
Mail this story
Print this story

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).

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

______________________________________________________________________________

                        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)

______________________________________________________________________________

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
    ftp://ftp.suse.com/pub/suse/i386/update/7.0/a1/modules-2.3.11-73.i386.rpm
      9643216a1e0c147635ef62d894a9d7ad

    source rpm:
    ftp://ftp.suse.com/pub/suse/i386/update/7.0/zq1/modules.spm
    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
    ftp://ftp.suse.com/pub/suse/i386/update/6.4/a1/modules-2.3.9-63.i386.rpm
      d3a95b93e549aae9a462e84d179efe45

    source rpm:
    ftp://ftp.suse.com/pub/suse/i386/update/6.4/zq1/modules.spm
    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
    ftp://ftp.suse.com/pub/suse/sparc/update/7.0/a1/modules-2.3.11-73.sparc.rpm
      c0ab9aab7a61cefdb2cade98c663d4e3

    source rpm:
    ftp://ftp.suse.com/pub/suse/sparc/update/7.0/zq1/modules.spm
    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
    ftp://ftp.suse.com/pub/suse/axp/update/6.4/a1/modules-2.3.9-63.alpha.rpm
      a88b84d7f3d79f2a47ff9e78681a0390

    source rpm:
    ftp://ftp.suse.com/pub/suse/axp/update/6.4/zq1/modules.spm
    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:
    ftp://ftp.suse.com/pub/suse/ppc/update/7.0/a1/modules-2.3.11-73.ppc.rpm
      ef09b5c6438a0de8e18653e0a60d9c4c
 
    source rpm:
    ftp://ftp.suse.com/pub/suse/ppc/update/7.0/zq1/modules.spm
    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
    ftp://ftp.suse.com/pub/suse/ppc/update/6.4/a1/modules-2.3.9-63.ppc.rpm
      27ba13500292c44969dd865f0c543c19

    source rpm:
    ftp://ftp.suse.com/pub/suse/ppc/update/6.4/zq1/modules.spm
    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.

______________________________________________________________________________

2) Pending vulnerabilities in SuSE Distributions and Workarounds:

    A seperate message is being prepared to address the currently ongoing
    security vulnerabilites.
______________________________________________________________________________

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

______________________________________________________________________________

    The information in this advisory may be distributed or reproduced,
    provided that the advisory is not modified in any way.
    SuSE GmbH makes no warranties of any kind whatsoever with respect
    to the information contained in this security advisory.

Type Bits/KeyID Date User ID
pub 2048/3D25D3D9 1999/03/06 SuSE Security Team <security@suse.de>

- -----BEGIN PGP PUBLIC KEY BLOCK-----
Version: 2.6.3i

mQENAzbhLQQAAAEIAKAkXHe0lWRBXLpn38hMHy03F0I4Sszmoc8aaKJrhfhyMlOA
BqvklPLE2f9UrI4Xc860gH79ZREwAgPt0pi6+SleNFLNcNFAuuHMLQOOsaMFatbz
JR9i4m/lf6q929YROu5zB48rBAlcfTm+IBbijaEdnqpwGib45wE/Cfy6FAttBHQh
1Kp+r/jPbf1mYAvljUfHKuvbg8t2EIQz/5yGp+n5trn9pElfQO2cRBq8LFpf1l+U
P7EKjFmlOq+Gs/fF98/dP3DfniSd78LQPq5vp8RL8nr/o2i7jkAQ33m4f1wOBWd+
cZovrKXYlXiR+Bf7m2hpZo+/sAzhd7LmAD0l09kABRG0JVN1U0UgU2VjdXJpdHkg
VGVhbSA8c2VjdXJpdHlAc3VzZS5kZT6JARUDBRA24S1H5Fiyh7HKPEUBAVcOB/9b
yHYji1/+4Xc2GhvXK0FSJN0MGgeXgW47yxDL7gmR4mNgjlIOUHZj0PEpVjWepOJ7
tQS3L9oP6cpj1Fj/XxuLbkp5VCQ61hpt54coQAvYrnT9rtWEGN+xmwejT1WmYmDJ
xG+EGBXKr+XP69oIUl1E2JO3rXeklulgjqRKos4cdXKgyjWZ7CP9V9daRXDtje63
Om8gwSdU/nCvhdRIWp/Vwbf7Ia8iZr9OJ5YuQl0DBG4qmGDDrvImgPAFkYFzwlqo
choXFQ9y0YVCV41DnR+GYhwl2qBd81T8aXhihEGPIgaw3g8gd8B5o6mPVgl+nJqI
BkEYGBusiag2pS6qwznZiQEVAwUQNuEtBHey5gA9JdPZAQFtOAf+KVh939b0J94u
v/kpg4xs1LthlhquhbHcKNoVTNspugiC3qMPyvSX4XcBr2PC0cVkS4Z9PY9iCfT+
x9WM96g39dAF+le2CCx7XISk9XXJ4ApEy5g4AuK7NYgAJd39PPbERgWnxjxir9g0
Ix30dS30bW39D+3NPU5Ho9TD/B7UDFvYT5AWHl3MGwo3a1RhTs6sfgL7yQ3U+mvq
MkTExZb5mfN1FeaYKMopoI4VpzNVeGxQWIz67VjJHVyUlF20ekOz4kWVgsxkc8G2
saqZd6yv2EwqYTi8BDAduweP33KrQc4KDDommQNDOXxaKOeCoESIdM4p7Esdjq1o
L0oixF12Cg==
=pIeS
- -----END PGP PUBLIC KEY BLOCK-----

-----BEGIN PGP SIGNATURE-----
Version: 2.6.3i
Charset: noconv

iQEVAwUBOg+vPXey5gA9JdPZAQFwXQf+LqkRkpXmx6QNnM6aihRsnBpElNC/6Ip5
to1SNRdg2GPKDIznbFLCOOhu0v4siIfpJs0nJEK2CNyZvV3iCL8RZlHasfJTD/6/
GTQtXAaxXHeEISfn/3Ouibf1WIjYDGC7mo444412feabOcZWhzG1p/11G1wgmU3T
mWUMDWY5IgL/0Qz00ghC6tXnt3YQQtgw5hFzxfxyJ91zh74WbMcyRvU4hyfiBq3w
uhGyU5gjkwWoGugWm3RfEByEtflah1yumfeuV6Fh3UF6dBRo878qM239ugxFQFYj
vIT5Qp4lvg48Cn1BpxTNQTA74qOwBVzb4QqlSTGh+kwMNwiIjsRpCA==
=/v2t
-----END PGP SIGNATURE-----



This archive was generated by hypermail 2.1.0 : Mon Jun 04 2001 - 18:25:15 PDT

  Nav
» Read more about: Story Type: Security; Groups: SUSE

« Return to the newswire homepage

This topic does not have any threads posted yet!

You cannot post until you login.