Cascading Attacks on Wi-Fi Networks with Weak Interferers

Abstract

Recent work shows that an adversary can exploit a coupling effect induced by hidden nodes to launch a cascading attack causing global congestion in a Wi-Fi network. The underlying assumption is that the power of interference caused by a hidden node is an order of magnitude stronger than the signal sent to the receiver. In this paper, we investigate the feasibility of cascading attacks with weakly interfering hidden nodes, that is when the signal-to-interference ratio is high. Through extensive ns-3 simulations, including for an indoor building model, we show that cascading attacks are still feasible. The attacks leverage two PHY-layer phenomena: receiver capture and bit rate adaptation. We show that the attack relies on a coupling effect, whereby the average bit rate of a transmission pair drops sharply as the channel utilization of a neighboring pair gets higher. This coupling effect facilitates the propagation of the attack throughout the network.