Fast chargers let users charge their smartphone batteries faster than normal by increasing the voltage. However, some fast chargers can destroy the devices and compromise the built-in firmware if they fall into hackers’ hands, according to a research from Xuanwu Labs, Tencent Security.
Xuanwu Labs researchers stated that the fast charger technology includes both power transmission and data transmission functions. They found that some manufacturers have designed interfaces with protocols that can read and write built-in firmware in the data channel, however they lack effective security verification of the read and write behavior of the technology. The fast charger protocol has a memory corruption issue which could be misused by an attacker to rewrite the firmware of the fast charging device and control the power supply behavior.
The researchers explained two possible attack scenarios dubbed as “BadPower” in which an attacker can invade a charger and other devices supporting fast charger technology. The researchers tested 35 out of the 234 fast charging devices, and found 18 devices with BadPower problems, and 11 devices that can be attacked through digital terminals.
Scenario 1: BadPower Attack Procedure Using Special Hardware
- The attacker uses a special device disguised as a mobile phone to connect to the charger’s charging port to invade the charger’s internal firmware.
- If one uses the hacked charger to charge other devices, the charger will perform a power overload attack on the powered device.
Scenario 2: BadPower Attack Procedure via a Common Terminal
- The attacker invades the user’s mobile phone, notebook computer and other terminal devices in some way, and implants malicious programs with BadPower attack capabilities in them, making the terminal device an attack agent of BadPower.
- When the user connects the terminal device to the charger, the malicious program in the terminal device invades the internal firmware of the charger.
- When the user uses the hacked charger to charge the device again, the charger will carry out a power overload attack on the powered device.
“Using BadPower, an attacker can hack into devices such as chargers that support fast charging technology, causing the intruded device to output an excessively high voltage when powering externally, resulting in breakdown and burning of the components of the powered device, and causes further damage to the powered device. The physical environment where the equipment is located creates a safety hazard,” the researchers explained.
Cyber Risks with Chargers
In a similar research, cybersecurity experts stated that using someone else charging cable might bring threats to mobile devices. Attackers could exploit charging cables/cords to access sensitive information from the victim’s mobile. They could implant malware into charging cords or cables to hack mobile devices. The USB chargers can be turned into potential hacking devices by inserting a malicious chip that allegedly allows attackers to access a mobile’s data over open Wi-Fi networks. The surprising part here is that the person who is lending the charger might not be aware that his/her charger is infected.