The security model of FreeSWITCH can be quite complex, To blame FreeSWITCH itself for your misconfiguration is downright FUD, If you have issues or questions on how to properly configure FreeSWITCH for this specific role you can just ask, many of us will help you create a configuration that would be robust and secure.  If you would have set 'disable-transfer', to true, and possibly 'disable-register' it would also help lower your attack surface, In addition you shouldn't open your system to the planet, thats irresponsible on your part for doing so.

FreeSWITCH isn't a firewall, so of course its weak because its NOT a firewall.

And these are in the configs:

    <!-- disable register and transfer which may be undesirable in a public switch -->

    <!--<param name="disable-transfer" value="true"/>-->

    <!--<param name="disable-register" value="true"/>-->

Thanks,

/b