CVE-2025-27840

medium

Description

Espressif ESP32 chips allow 29 hidden HCI commands, such as 0xFC02 (Write memory).

References

https://x.com/pascal_gujer/status/1898442439704158276

https://www.tarlogic.com/news/backdoor-esp32-chip-infect-ot-devices/

https://reg.rootedcon.com/cfp/schedule/talk/5

https://github.com/TarlogicSecurity/Talks/blob/main/2025_RootedCon_BluetoothTools.pdf

https://flyingpenguin.com/?p=67838

https://cheriot.org/auditing/backdoor/2025/03/09/no-esp32-style-backdoor.html

https://www.bleepingcomputer.com/news/security/undocumented-commands-found-in-bluetooth-chip-used-by-a-billion-devices/

https://www.espressif.com/en/news/Response_ESP32_Bluetooth

https://www.bleepingcomputer.com/news/security/undocumented-backdoor-found-in-bluetooth-chip-used-by-a-billion-devices/

https://news.ycombinator.com/item?id=43308740

https://news.ycombinator.com/item?id=43301369

https://github.com/orgs/espruino/discussions/7699

https://github.com/esphome/esphome/discussions/8382

https://github.com/em0gi/CVE-2025-27840

https://darkmentor.com/blog/esp32_non-backdoor/

Details

Source: Mitre, NVD

Published: 2025-03-08

Updated: 2025-03-12

Risk Information

CVSS v2

Base Score: 5.9

Vector: CVSS2#AV:L/AC:L/Au:M/C:C/I:C/A:N

Severity: Medium

CVSS v3

Base Score: 6.8

Vector: CVSS:3.0/AV:P/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N

Severity: Medium

EPSS

EPSS: 0.00221