matrix-appservice-irc allows IRC Command injection in provisioning API

matrix-appservice-irc is a Node.js IRC bridge for the Matrix messaging protocol. The provisioning API of the matrix-appservice-irc bridge up to version 3.0.2 contains a vulnerability which can lead to arbitrary IRC command execution as the bridge IRC bot. The vulnerability has been patched in matrix-appservice-irc version 3.0.3.