<p>➀ A hidden feature in ESP32 microcontrollers, widely used in IoT devices, poses potential security risks including device spoofing, data theft, and malware installation.</p><p>➁ This vulnerability stems from the undocumented commands in the Bluetooth Host Controller Interface (HCI) protocol, which could allow attackers to bypass standard security checks and compromise critical systems.</p><p>➂ Recommendations to mitigate risks include auditing firmware, disabling unused Bluetooth services, ensuring secure firmware updates, and implementing strong authentication mechanisms.</p>