If anyone else ever needs this, here is a pin map of Renesas RL78/F13. Pads with ? are power supply, but there seems to be a bit too many of them, maybe for bonding options.
Broadcom and Cypress chips have the same HCI "backdoor" allowing to write to the Bluetooth chip's RAM. This feature is used for firmware patches.
We didn't request CVEs for that 9 years ago. Instead, we built the InternalBlue Bluetooth research framework.
https://github.com/seemoo-lab/internalblue
I’ve posted a detailed explanation of why the claimed ESP32 Bluetooth chip “backdoor” is not a backdoor. It’s just a poor security practice, which is found in other Bluetooth chips by vendors like Broadcom, Cypress, and Texas Instruments too. https://darkmentor.com/blog/esp32_non-backdoor/
The tension between vulnerability power and exploit technique flexibility
Stop devaluing your writing by slapping an ugly as fuck error-ridden AI image on your article/blogpost/newsletter.
The second oldest digital computer in the world is now working 🙂🤷♂️
Well done @usagielectric for getting it in a running state!
The oldest is the Harwell Dekatron at @tnmoc in Bletchley Park, which is also very cool and well worth visiting 😁🖖
It's easy to get scared when headlines combine terms like "backdoor", "Bluetooth", and "a billion devices".
Should you be worried? No.
The "attack" for ESP32 chips in some Internet of Things devices is some undocumented commands that are likely to be for testing by the manufacturer, Espressif, the in the factory. It cannot spread from one device to another like a virus/worm, and it takes a lot more than being within Bluetooth range -- it requires physical access to I/O pins on the chip itself or access to a USB port (if one is present). That's just the standard way to flash the firmware. It should go without saying that if a malicious person has physical access to the inside of your device then you may have more security concerns.
It's been fascinating to watch the propagation of fear and misinformation in a niche where I have dabbled enough to develop a bit of technical proficiency.
My interpretation of events is that Tarlogic Security is spreading panic to gain attention or notoriety.
Undocumented "backdoor" found in Bluetooth chip used by a billion devices:
https://www.bleepingcomputer.com/news/security/undocumented-backdoor-found-in-bluetooth-chip-used-by-a-billion-devices/
NIST (National Institute of Standards and Technology) has a CVE:
https://nvd.nist.gov/vuln/detail/CVE-2025-27840
Edit to update:
Espressif’s Response to Claimed Backdoor and Undocumented Commands in ESP32 Bluetooth Stack
https://www.espressif.com/en/news/Response_ESP32_Bluetooth
Schrödinger's audit: Companies are found compliant until they are compromised, in which case they will always be found out of compliance.