hackspace
https://www.bleepingcomputer.com/news/security/undocumented-backdoor-found-in-bluetooth-chip-used-by-a-billion-devices/
Espressif
Espressif’s Response to Claimed Backdoor and Undocumented Commands in ESP32 Bluetooth Stack | Espressif Systems
Recently, some media have reported on a press release initially calling out ESP32 chips for having a “backdoor”. Espressif would like to take this opportunity to clarify this matter for our users and partners.