Asterisk 20.1.0 Denial Of Service

When handling DTLS-SRTP for media setup, Asterisk version 20.1.0 is susceptible to denial of service due to a race condition in the hello handshake phase of the DTLS protocol. This attack can be done continuously, thus denying new DTLS-SRTP encrypted calls during the attack.

asterisk attack denial of service dtls encrypted handling handshake hello media protocol race race condition service version