Re: Voice over IP

[Dug Song <dugsong () monkey org>]

On Thu, Jun 14, 2001 Brandon Young wrote:

> A couple of colleagues and I are working on a security audit for a
> VOIP system. Anyone know of any exploits and vulnerabilities that may
> exist with Cisco's call manager? One thing we have found is that the
> traffic can be sniffed during phone calls. TCP is used for the
> initial connection setup and then once the phone has setup a session
> to the call manager it then uses the RTP protocol. We found that the
> conversation is placed in the PCMU audio codec. We are looking to
> find a way to extract the payloads and reassemble the audio so that
> we can play back the phone conversations.  We are also looking at 
> launching a man in the middle attack and getting access to the
> conversation and trying and listen to it in real time instead of
> capturing and replaying. Any ideas on some possible ways to execute
> this? 

soon to be integrated into the dsniff suite:

        http://www.monkey.org/~provos/vomit/

decode and convert Cisco IP phone calls into .wav format for playback
(either realtime or from a tcpdump capture), and inject .wav data into
ongoing telephone conversations.

be sure to leave a tip for Niels. :-)

-d.

p.s. he really does leave me those kind of crazy messages...

---
http://www.monkey.org/~dugsong/