A security researcher has shown that disrupting WiFi, Bluetooth, and ZigBee networks isn't difficult, but most importantly, it's not as costly as you might think.
According to Mathy Vanhoef, a PhD student at KU Leuven (Belgium), this can be easily done with a $ 15 Wi-Fi dongle bought from Amazon, a Raspberry Pi board, and an amplifier that extends the range of the attack on some extended 120 meters.
The attack would hit all devices within range that work in the 2.4 and 5 GHz bands.
Given that the above networks are critical to the functioning of many IoT devices and systems - home security systems, car locks, baby monitors, etc. - it should be clear that the fact that these attacks can be carried out so easily and cheaply , can lead to serious consequences.
In fact, cheap wifi jammer is known to be already used by crooks around the world:
This is why it is important that defenders can detect these attacks if they continue, even if they cannot stop them.
During his recent presentation at BruCON, Vanhoef stated that by changing the dongle's firmware, he could force the target networks to always give priority to the device's transmissions. If the device is transmitting continuously, it means that all other devices cannot, effectively rendering the channel unusable.
His attempts at selectively jamming (blocking certain packets) were less successful, and he concluded that 100% reliable selective jamming is not possible.
He also says these low-level jamming attacks could affect attacks on higher-level protocols. For example, he says they can be used to launch a channel-based MiTM attack against WPA's still widely used Temporal Key Integrity Protocol (TKIP).