Brandon, I can name few security hazards with VoIP (there are a lot more): 1. Traffic can be sniffed and played back (NAI got sniffer pro module for this already, there are couple free tools on the net). 2. Denial-of-Service on the conversation - if you have the correct SSID than you can introduce background noise inside the conversation. 3. Denial-of-Service on the talk itself - you might be able to stop the actual talk when using the used SSID between source A and source B for Source C to Source A (can be as well Source C to Source B). 4. Spoofing signals - terminating talks, initiating non-existing talks... etc. Let see your face at 4am after I spoofed the 'ring' to your house :) Or I falsified signals so the exchange will think you are using your phone all the time... :) 5. Denial of Service on the Call Manager itself (joint IP/Voice network I remind you) 6. Man in the middle is not simple even if you are located somewhere between the two ends. You have problem of LATENCY... so this is not obvious to do I hope this gives you some points to work on :) There are others but they are related to carrier grade Telco setups. Ofir Arkin [ofir@sys-security.com] Founder The Sys-Security Group http://www.sys-security.com PGP CC2C BE53 12C6 C9F2 87B1 B8C6 0DFA CF2D D360 43FA -----Original Message----- From: Young, Brandon [mailto:byoungat_private] Sent: ? 14 ???? 2001 17:48 To: 'pen-testat_private' Subject: Voice over IP -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 All, 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? Thanks in advance, //CALENCE Brandon Young Consultant - Consulting Services 480.889.9736 byoungat_private www.calence.com -----BEGIN PGP SIGNATURE----- Version: PGPfreeware 7.0.3 for non-commercial use <http://www.pgp.com> iQA/AwUBOyjc1HTH1Q5UAycjEQLCfgCfaesfZXb/E35EaTqE9sZdcPCZlGsAoJxf wh1QNRb61/lEJMHS5LhUDMS6 =atyJ -----END PGP SIGNATURE-----
This archive was generated by hypermail 2b30 : Thu Jun 14 2001 - 17:47:04 PDT