RE: VoIP Assessment

["Bob Bell (rtbell)" <rtbell () cisco com>]

Mark, Intel96 - 

There are a lot of conflicting opinions floating around as to the
security of VoIP systems. One of the things that you need to do is
establish whether you are dealing with a bounded system, (i.e. an
enterprise PBX replacement) or an unbounded one (i.e. SKYPE) as they
have considerable differences in both their vulnerability and the
resources available to deal with issues. Secondly, security of VoIP is
not a single dimensional problem. Many of the issues of protecting VoIP
occur a layers far below the application layer which is where VoIP
lives. So, you need to examine the issue from a systems approach not
simply a point solution for VoIP. Finally, there is a great deal more to
providing SYSTEMIC protection beyond simply protecting the protocol.
This includes things like the provisioning of the endpoints, the control
of and validation of the images contained in the endpoints, the
authentication and authorization schemes for the endpoints and users,
etc. If I can be of help, please feel free to contact me.

Bob 

IPCBU Security Architect
Cisco Systems, Inc.
576 S. Brentwood Ln.
Bountiful, UT 84010
801-294-3034 (v)
801-294-3023 (f)
801-971-4200 (c)
rtbell () cisco com
 

> -----Original Message-----
> From: Mark Teicher [mailto:mht3 () earthlink net] 
> Sent: Tuesday, July 19, 2005 16:40
> To: intel96
> Cc: pen-test () securityfocus com
> Subject: Re: VoIP Assessment
>
> What specific items have you been tasked to validate?
> Could be as simple as :
>          Are the components VoIP capable?
>                  If so, then what protocols have been 
> implemented (Y/N)
>                     If x protocol, if implemented correctly 
> (i.e when enabled, does it process the traffic correctly (Y/N)
>                           If x protocol, if implemented 
> correctly (i.e. when x protocol is disabled, does it block 
> VoIP traffic inbound/outbound? (Y/N)
>
> and so and so on
>
> Lots of those "security" type experts will overstate the 
> obvious and start rattling off big words like MITM attacks, 
> Resource exhaustion,
> H.323 attacks, SIP Overflow attacks, etc, etc, but IMHO, 
> simplify what the tasks are, and break those tasks into 
> simple steps that any former senior security consultant can 
> do by utilizing a checklist approach, otherwise one gets into 
> the battle with the "puffed out chest security wannabes "
>
> /m
> At 01:40 PM 7/19/2005, intel96 wrote:
> > I have been asked to look at the security of a VoIP 
> architecture.  Has 
> > anyone conducted a security assessment against VoIP or the 
> components 
> > that make up the architecture?
> >
> > Thanks,
> >
> > Intel96