Vulnerable Keyless Entry RF Protocol Enables Replay Attack on Yadea T5 Electric Bicycles

Yadea T5 Electric Bicycles (models manufactured in/after 2024) have a weak authentication mechanism in their keyless entry system. The system utilizes the EV1527 fixed-code RF protocol without implementing rolling codes or cryptographic challenge-response mechanisms. This is vulnerable to signal forgery after a local attacker intercepts any legitimate key fob transmission, allowing for complete unauthorized vehicle operation via a replay attack.