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VOIP Network Threats

Let the subscribers beware

Gerard Wilkes October 24, 2006

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VOIP Landscape IP networks are increasingly being

used to carry voice, video, and other communication streams.

New IP voice applications will emerge encouraging the further adoption of this technology.

The combined services provide triple the attack targets and triples the risk.

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VOIP Protocols

SIP – Call Signaling RTP – Message Transport RTCP – Control Protocol

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VOIP Vulnerabilities

Eavesdropping – Sniffing SIP Signals Identity Spoofing – Call Redirection Identity and Toll Fraud – Stolen

Credentials Call Integrity – Altered Voice Packets DOS – Against SIP, RTP

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Interception Attack

AttackerPING PING

Phone-APhone-B

192.168.1.100:50:56:01:01:01

192.168.1.200:50:56:01:01:02

192.168.1.500:50:56:01:01:05

192.168.1.1 00:50:56:01:01:01

192.168.1.200:50:56:01:01:02

192.168.1.1 192.168.1.2

ARP Spoof

To get to 192.168.1.2 useMAC 00:50:56:01:01:05

ARP Spoof

To get to 192.168.1.1 useMAC 00:50:56:01:01:05

ARP Spoofing on Switched LAN

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Interception Attack

AttackerPhone-APhone-B

192.168.1.100:50:56:01:01:01

192.168.1.200:50:56:01:01:02

192.168.1.500:50:56:01:01:05

Call Interception

SIP INVITE to Phone-B Forward SIP INVITE

to Phone-B

SIP Response to Phone-A

Forward SIP Response to Phone-A

Conversation

RTP (UDP) RTP (UDP)

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Interception Attack

Attacker

Conversation