[OpenSER-Users] Security hole in REGISTER's Contact using domain

[Iñaki Baz Castillo]

El Friday 14 December 2007 07:02:37 Juha Heinanen escribió:
> Iñaki Baz Castillo writes:
>  > How to handle it? is it not a real security hole?
>
> 1) buy pstn gws that accept no hostnames (just its own ip address) in
>   the hostpart of r-uri.  example, cisco ios with later software
>   releases.

So really isn't there solution just in OpenSer-Registrar side??


> 2) forget the hostpart check all together and instead check the
>    userpart, where you have put something special that the gw then
>    removes.

So you mean for example:

register.deny:
--------------------
  ALL : "^sip:.*secret_word_.*@"
----------------------

And later, in any call to PSTN OpenSer should add:

  $ru = "secret_word_" + $ru;

so the uri arriving to the gw becomes:

  sip:secret_word_01666555444 at gw_ip_or_hostname

And the gw should just allow calls from OpenSer with urri username beginning 
with  "secret_word_" and it should strip it.


Is this what you mean? anyway, a little complex, isn't it?  XDD



Regards.



-- 
Iñaki Baz Castillo
ibc at in.ilimit.es