A security researcher showed that destroying WLAN, Bluetooth and ZigBee networks is not difficult, but most importantly, it is not as expensive as you think. According to Mathie Vanhoef, a doctoral student at KU Leuven, Belgium, you only need to buy a $15 Wi-Fi dongle from Amazon, a Raspberry Pi board and an amplifier that can expand the attack range. This operation is somewhat extended. 120 meters.
The attack will affect all portable jammer devices operating in the 2.4 GHz and 5 GHz frequency bands. Since the aforementioned network is critical to the functioning of many IoT devices and systems (home security systems, car locks, baby monitors, etc.), it should be understood that these attacks can be carried out so easily and cheaply, and may have serious consequences.
In fact, it is well known that scammers all over the world are already using cheap jammers: therefore, it is important that defenders continue to discover them even if they cannot stop the attack. Vanhoef said in BruCON’s latest speech that changing the dongle’s firmware may force the target network to always prioritize device transmission. If the device transmits continuously, it means that no other device can transmit, which actually makes the channel unavailable.
His attempt at selective blocking (blocking certain packets) was not very successful. He concluded that selective blocking cannot be performed with 100% reliability. He also said that these low-level interference attacks may affect attacks on higher-level protocols. He said, for example, they can be used to launch channel-based MiTM attacks against Temporal Key Integrity Protocol (TKIP), which is still widely used by WPA.