/etc/dbus-1/system.d/NetworkManager.conf:

gistfile1.txt

<!DOCTYPE busconfig PUBLIC
 "-//freedesktop//DTD D-BUS Bus Configuration 1.0//EN"
 "http://www.freedesktop.org/standards/dbus/1.0/busconfig.dtd">
<busconfig>
        <policy user="root">
                <allow own="org.freedesktop.NetworkManager"/>
                <allow send_destination="org.freedesktop.NetworkManager"/>
                <allow send_interface="org.freedesktop.NetworkManager"/>

        <allow own="org.freedesktop.NetworkManager.PPP"/>
                <allow send_destination="org.freedesktop.NetworkManager.PPP"/>
                <allow send_interface="org.freedesktop.NetworkManager.PPP"/>
        </policy>
    <!-- My hack -->
        <policy group="network">
                <allow send_destination="org.freedesktop.NetworkManager"/>
                <allow send_interface="org.freedesktop.NetworkManager"/>
        </policy>
        <!-- End of my hack -->
        <policy at_console="true">
                <allow send_destination="org.freedesktop.NetworkManager"/>
                <allow send_interface="org.freedesktop.NetworkManager"/>
        </policy>
        <policy context="default">
                <deny own="org.freedesktop.NetworkManager"/>
                <deny send_destination="org.freedesktop.NetworkManager"/>
                <deny send_interface="org.freedesktop.NetworkManager"/>

                <deny own="org.freedesktop.NetworkManager.PPP"/>
                <deny send_destination="org.freedesktop.NetworkManager.PPP"/>
                <deny send_interface="org.freedesktop.NetworkManager.PPP"/>
        </policy>

        <limit name="max_replies_per_connection">512</limit>
</busconfig>