The default permissions on /dev/kmem is insecure
Posted by LinuxSecurity.com Team   
SuSE The default permissions on /dev/kmem is insecure. A bug in all Linux 2.0.x kernels except 2.0.36 have a vulnerability which makes blind ip-spoofing possible.


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                        SuSE Security Announcement

        Packages: devs-*
                  linux-2.0.35 and below
        Date:     Thu Mar 18 10:22:11 CET 1999
        Affected: SuSE 6.0 and below, other Linux distributions
                  SuSE 5.3 and below, other Linux distributions

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A security hole was discovered in the package mentioned above.
Please update as soon as possible or disable the service if you are using
this software on your SuSE Linux installation(s).

Other Linux distributions or operating systems might be affected as
well, please contact your vendor for information about this issue.

Please note, that that we provide this information on as "as-is" basis only.
There is no warranty whatsoever and no liability for any direct, indirect or
incidental damage arising from this information or the installation of
the update package.

______________________________________________________________________________

1. Problem Description

    The default permissions on /dev/kmem is insecure.

    A bug in all Linux 2.0.x kernels except 2.0.36 have a vulnerability
    which makes blind ip-spoofing possible.

2. Impact

    If programs like lsof have got vulnerabilities (like buffer overflows)
    root access can easily be obtained.
    Note that lsof *had* a buffer overflow, for which SuSE issued a bug fix
    some time ago. Please ensure that you installed it.

    IP addresses used for authentication or logging can't be relied on.
    If services which rely on trust are used on a system, remote access
    to a system can be obtained.
    No authentication should rely on IP addresses anyway ...

3. Solution

    Execute the following command:

        /bin/chmod 640 /dev/kmem

    Install the 2.0.36 or a 2.2.x kernel.
    They are available from our webserver (see below)

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Here is the md5 checksum of the upgrade package, please verify this
before installing the new package:

a0b520d70026ef236efd2c7d7c87b233  linux-2.0.36.tar.gz
3e737f6f33534dd15c440cc5c51ebcb5  linux-2.0.36.SuSE.tgz
4bd690ca533b6c07e2f81f160e59ee6c  linux-2.2.3.tar.gz

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You will find the update on our ftp-Server:

        ftp://ftp.suse.com/pub/suse_update/kernel/
        http://www.suse.de/patches/index.html

or try the following web pages for a list of mirrors:

        http://www.suse.de/ftp.html
	http://www.suse.com/en/ftp.html

______________________________________________________________________________

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______________________________________________________________________________

If you want to report *NEW* security bugs in the SuSE Linux Distribution
please send an email to security@suse.de or call our support line.
You may use pgp with the public key below to ensure confidentiality.
______________________________________________________________________________

  This information is provided freely to everyone interested and may
  be redistributed provided that it is not altered in any way.

Type Bits/KeyID    Date       User ID
pub  2048/3D25D3D9 1999/03/06 SuSE Security Team