RedHat: usermode vulnerability
Posted by LinuxSecurity.com Team   
RedHat Linux Console users can obtain root privileges
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                   Red Hat, Inc. Security Advisory

Synopsis:          Updated usermode packages.
Advisory ID:       RHSA-2000:053-01
Issue date:        2000-08-11
Updated on:        2000-08-11
Product:           Red Hat Linux
Keywords:          usermode shutdown
Cross references:  N/A
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1. Topic:

Updated usermode packages are now available for Red Hat Linux 6.0, 6.1, and
6.2.

2. Relevant releases/architectures:

Red Hat Linux 6.0 - i386, alpha, sparc
Red Hat Linux 6.1 - i386, alpha, sparc
Red Hat Linux 6.2 - i386, alpha, sparc
Red Hat Linux 6.2E - i386, alpha, sparc

3. Problem description:

The usermode package allows unprivileged users logged in at the system
console to run the halt, poweroff, reboot, and shutdown commands without
needing to know the superuser's password.  While being able to halt,
poweroff, and reboot is a desirable thing, an unprivileged user can also
bring the system to single-user mode by running "shutdown now" with no
additional flags.  This update removes the "shutdown" command from the list
of commands unprivileged users can run.

4. Solution:

For each RPM for your particular architecture, run:

rpm -Fvh [filename]

where filename is the name of the RPM.

5. Bug IDs fixed  (http://bugzilla.Red Hat.com/bugzilla for more info):

13768 - Auth dialogs show "Picture of a key" text instead of graphic
13616 - Missing icon.
12433 - /usr/sbin/userhelper not stripped
11006 - kppp either doesn't display locally or remotely
9746 - Local user can go into single mode only with shutdown now...


6. RPMs required:

Red Hat Linux 6.0, 6.1, 6.2:

sparc: 
ftp://updates.Red Hat.com/6.2/sparc/usermode-1.28-2.sparc.rpm

alpha: 
ftp://updates.Red Hat.com/6.2/alpha/usermode-1.28-2.alpha.rpm

i386: 
ftp://updates.Red Hat.com/6.2/i386/usermode-1.28-2.i386.rpm

sources: 
ftp://updates.Red Hat.com/6.2/SRPMS/usermode-1.28-2.src.rpm

7. Verification:

MD5 sum                           Package Name
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24f2766589d1a16ebcda912067173396  6.2/SRPMS/usermode-1.28-2.src.rpm
94423f4138477d9d47a055ed3c4b3648  6.2/alpha/usermode-1.28-2.alpha.rpm
b8f16bb02c4355a86183e268bd57ac74  6.2/i386/usermode-1.28-2.i386.rpm
e1c2b7626a905f64b03f48127e742259  6.2/sparc/usermode-1.28-2.sparc.rpm

These packages are GPG signed by Red Hat, Inc. for security.  Our key
is available at:
     http://www.Red Hat.com/corp/contact.html

You can verify each package with the following command:
    rpm --checksig  

If you only wish to verify that each package has not been corrupted or
tampered with, examine only the md5sum with the following command:
    rpm --checksig --nogpg 

8. References:

N/A


Copyright(c) 2000 Red Hat, Inc.