29 Undocumented commands found in ESP-32 microcontrollers CVE-2025-27840 (www.bleepingcomputer.com)
from j4k3@lemmy.world to privacy@lemmy.ml on 10 Mar 07:09
https://lemmy.world/post/26598539

cross-posted from: programming.dev/post/26664400

Tarlogic developed a new C-based USB Bluetooth driver that is hardware-independent and cross-platform, allowing direct access to the hardware without relying on OS-specific APIs.

Armed with this new tool, which enables raw access to Bluetooth traffic, Tarlogic discovered hidden vendor-specific commands (Opcode 0x3F) in the ESP32 Bluetooth firmware that allow low-level control over Bluetooth functions.

In total, they found 29 undocumented commands, collectively characterized as a “backdoor,” that could be used for memory manipulation (read/write RAM and Flash), MAC address spoofing (device impersonation), and LMP/LLCP packet injection.

Espressif has not publicly documented these commands, so either they weren’t meant to be accessible, or they were left in by mistake. The issue is now tracked under CVE-2025-27840.

#privacy

threaded - newest

KickMeElmo@sopuli.xyz on 10 Mar 08:14 next collapse

Seems more like a feature considering how ESP32s are used.

j4k3@lemmy.world on 10 Mar 08:19 collapse

They are in a lot of IoT devices that are not hobby and dev related too. Like my folk’s smoker grill has one that is also on a ridiculous AWS connection and designed to try and stay on 24/7 like proper stalkerware nonsense.

sh3llcmdr@feddit.uk on 10 Mar 08:33 collapse

darkmentor.com/blog/esp32_non-backdoor/

There are a number of explanations for those Opcodes. Seems like quite a few knowledgeable peeps are wading in to explain what they think the researchers are seeing. The most open peer review ever!!

jjagaimo@sh.itjust.works on 10 Mar 10:27 next collapse

Notca backdoor, just undocumented commands on the hci. You would already need access to the device from the microcontroller side to leverage them. Also it’s not uncommon for older devices like this to have undocumented commands

HappyFrog@lemmy.blahaj.zone on 10 Mar 11:43 next collapse

I don’t see a spooky name and a logo; this is a dud.

BOFH666@lemmy.world on 10 Mar 19:38 collapse

The statement from Espressif:

www.espressif.com/en/…/Response_ESP32_Bluetooth