The login user list must be disabled.

From Red Hat Enterprise Linux 6 Security Technical Implementation Guide

Associated with: CCI-000366

SV-55880r2_rule The login user list must be disabled.

Vulnerability discussion

Leaving the user list enabled is a security risk since it allows anyone with physical access to the system to quickly enumerate known user accounts without logging in.

Check content

If the GConf2 package is not installed, this is not applicable. To ensure the user list is disabled, run the following command: $ gconftool-2 --direct \ --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \ --get /apps/gdm/simple-greeter/disable_user_list The output should be "true". If it is not, this is a finding.

Fix text

In the default graphical environment, users logging directly into the system are greeted with a login screen that displays all known users. This functionality should be disabled. Run the following command to disable the user list: $ sudo gconftool-2 --direct \ --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \ --type bool --set /apps/gdm/simple-greeter/disable_user_list true

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