Black Hat Briefings, Usa 2007 [audio] Presentations From The Security Conference.

The Realtime Transport Protocol (RTP) is a common media layer shared between H.323, SIP, and Skinny (SCCP) VoIP deployments. RTP is responsible for the actual voice/audio stream in VoIP networks; hence attacks against RTP are valid against the bulk VoIP installations in enterprise environments. Since signaling (H.323/SIP/SCCP) and media transfer (RTP) are handled by two separate protocols, injecting audio into a stream is often the most damaging attack against RTP. RTP is vulnerable to audio injection due to its lack of integrity protection and its wide tolerance of sequence information. The presentation will demonstrate an easy to use GUI VoIP injection attack tool for RTP appropriately named RTPInject. The tool, with zero setup prerequisites, allows an attacker to inject arbitrary audio into an existing conversation involving at least one VoIP endpoint. RTPInject automatically detects RTP streams on the wire, enumerates the codecs in use, and displays this information to the user. The user can then selec