An issue was discovered in the Espressif ESP32 mask ROM code 2016-06-08 0 through 2. Lack of anti-glitch mitigations in the first stage bootloader of the ESP32 chip allows an attacker (with physical access to the device) to read the contents of read-protected eFuses, such as flash encryption and secure boot keys, by injecting a glitch into the power supply of the chip shortly after reset.
Published November 15, 2019.