RE: pentesting voip network-please help

["McGhee, Eddie" <Eddie.McGhee () ncr com>]

Hi Marco,

There is usually two tftps configured for the 7941 phone, I would check in settings and try to connect to the second 
tftp if available. These are available off these Settings -> Network configuration -> options 8 and 9 on 7941 I have on 
my desk here.

Next I would look at where the busiest/most interesting RTP packets are coming from and choose which hosts to poison, 
if it is possible, get the IP's of staff high in the organization and arp poison these clients then sniff away.

Last piece of advice may be relevant or not but backtrack is fully loaded with great tools for pentesting VOIP, is this 
what you are using?

Regards

 phed

-----Original Message-----
From: listbounce () securityfocus com [mailto:listbounce () securityfocus com] On Behalf Of mzcohen2682 () aim com
Sent: 29 January 2010 18:16
To: pen-test () securityfocus com
Subject: pentesting voip network-please help





 hi all !!

im doing an internal (lan) pentest for a voip network. the network has
6 cisco call manager version 6.1.3 as a cluster. they have cisco phones
7911 and 7941. they use a seperate vlan por the voip network.

I started by trying to download the images files for the phones from the tftp server by doing a brute force attack for 
the names of the files.

I have access to one of the 7941 phones so I checked that the verion of the image is 4.0/8.0 (9.0) in not sure what 
should be the names for the file images that the phones reload after boot but according to cisco documentation there 
must be SIPdefault.cnf and OS79xx.txt on the root directory of the tftp server. but I tried and there are not..

so what are the nemes of the files? I read a documents that said that if im am able to download those files I will find 
lots of interseting information like phone passwords etc..

after that... I tried to capture some RTP conversations but without any success. I am connected to the voip vlan and 
used wireshark but It doesnt detect any calles ! shoud I do some arp spoofing attack? but to which mac's?

any other ideas how to continue with this pentest?

what I see is that although the client didnt implement encryption or any other security control just the vlan isnt not 
so eaxy to pentest a voip network..

thanks

marco





  

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This list is sponsored by: Information Assurance Certification Review Board

Prove to peers and potential employers without a doubt that you can actually do a proper penetration test. IACRB CPT 
and CEPT certs require a full practical examination in order to become certified.

http://www.iacertification.org
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