Asterisk IAX2 Multiple Method Handshake Spoofing DoS
Medium Nessus Plugin ID 32132
SynopsisThe remote VoIP service can be abused to conduct an amplification attack against third-party hosts.
DescriptionThe version of Asterisk running on the remote host does not properly validate an IAX2 handshake. By spoofing NEW and ACK messages, an unauthenticated, remote attacker may be able to leverage this issue to flood a third-party host with packets from the affected host containing audio data.
SolutionUpgrade to Asterisk 1.4.20 / 1.2.28, Asterisk Business Edition C.1.8.1 / B.2.5.2, AsteriskNOW 1.0.3, s800i (Asterisk Appliance) 22.214.171.124 or later.