How to enable users to automount CD-ROM or USB in XFCE

I’m trying to install XFCE with ubuntu minimal iso (mini.iso).

With default settings, users are not able to mount CD-ROM or USB.

In order to change this, edit the following;

/usr/share/polkit-1/actions/org.freedesktop.udisks.policy

In the section “Mount a device”, change “allowed_any” and “allow_inactive” to “yes”.

<xmp>
  <action id="org.freedesktop.udisks.filesystem-mount">
    <description>Mount a device</description>
    <defaults>
      <allow_any><strong>yes</allow_any>
      <allow_inactive>yes</allow_inactive>
      <allow_active>yes</allow_active>
    </defaults>
  </action>
</xmp>