A security researcher has demonstrated that jamming WiFi, Bluetooth and Zigbee networks is not difficult to achieve but, above all, not as expensive as one might think.
According to Mathy Vanhoef, a PhD student at KU Leuven (Belgium), this can easily be done using a $15 Wi-Fi dongle purchased from Amazon, a Raspberry Pi board, and an amplifier that will expand the attack's reach to certain people. . 120 meters.
The attack would affect all devices within range that operate in the 2.4Ghz and 5 GHz bands.
The networks mentioned above being crucial for the operation of many IoT devices and systems - home security systems, car locks, baby monitors, etc. -, it should be obvious that the fact that these attacks can be carried out so easily and cheaply can lead to the serious consequences.
In fact, cheap wifi jammer are known to be used by scammers all over the world:
That's why it's crucial for defenders to be able to detect these attacks as they continue, even if they can't stop them.
During his recent presentation at BruCON, Vanhoef explained that by modifying the firmware of the dongle, he was able to force target networks to always prioritize transmissions from the device. If the device is designed to stream, that means all other devices won't be able to stream, effectively rendering the channel unusable.
His attempts at selective jamming (blocking of specific packets) were less successful, and he concluded that 100% reliable selective jamming is not possible.
He also says that these low-level jamming attacks could influence attacks on higher-level protocols. For example, he says they can be used to mount a channel-based MiTM attack against WPA's Temporal Key Integrity Protocol (TKIP), which is still widely used.