CVE-2025-27840

Espressif ESP32 chips allow 29 hidden HCI commands, such as 0xFC02 (Write memory).
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTNIST
6.8 MEDIUM
PHYSICAL
HIGH
HIGH
CVSS:3.1/AV:P/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:L
mitreCNA
6.8 MEDIUM
CVSS:3.1/AV:P/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:L
CISA-ADPADP
---
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Base Score
CVSS 3.x
EPSS Score
Percentile: 27%
VendorProductVersion
espressifesp32_firmware
-
𝑥
= Vulnerable software versions
Common Weakness Enumeration
References
https://cheriot.org/auditing/backdoor/2025/03/09/no-esp32-style-backdoor.html
https://darkmentor.com/blog/esp32_non-backdoor/
https://flyingpenguin.com/?p=67838
https://github.com/TarlogicSecurity/Talks/blob/main/2025_RootedCon_BluetoothTools.pdf
https://github.com/em0gi/CVE-2025-27840
https://github.com/esphome/esphome/discussions/8382
https://github.com/orgs/espruino/discussions/7699
https://news.ycombinator.com/item?id=43301369
https://news.ycombinator.com/item?id=43308740
https://reg.rootedcon.com/cfp/schedule/talk/5
https://www.bleepingcomputer.com/news/security/undocumented-backdoor-found-in-bluetooth-chip-used-by-a-billion-devices/
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.tarlogic.com/news/backdoor-esp32-chip-infect-ot-devices/
https://x.com/pascal_gujer/status/1898442439704158276