VulnerabilityAnalyzed
CVE-2025-27840
Espressif ESP32 chips allow 29 hidden HCI commands, such as 0xFC02 (Write memory).
MEDIUM 6.8EPSS 1.34%
Does this matter?
Lower severity and a low EPSS score (1.34%). Track it; it rarely justifies an emergency change on its own.
Description
Espressif ESP32 chips allow 29 hidden HCI commands, such as 0xFC02 (Write memory).
- CVSS 3.1
- 6.8 MEDIUMCVSS:3.1/AV:P/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N
- EPSS
- 1.34% probability · 70th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-912
- Affected
- espressif/esp32 firmware
- Source
- cve@mitre.org
References
- https://cheriot.org/auditing/backdoor/2025/03/09/no-esp32-style-backdoor.htmlTechnical Description, Third Party Advisory
- https://darkmentor.com/blog/esp32_non-backdoor/Exploit, Technical Description, Third Party Advisory
- https://flyingpenguin.com/?p=67838Technical Description, Third Party Advisory
- https://github.com/TarlogicSecurity/Talks/blob/main/2025_RootedCon_BluetoothTools.pdfThird Party Advisory
- https://github.com/em0gi/CVE-2025-27840Product
- https://github.com/esphome/esphome/discussions/8382Issue Tracking
- https://github.com/orgs/espruino/discussions/7699Issue Tracking
- https://news.ycombinator.com/item?id=43301369Issue Tracking
- https://news.ycombinator.com/item?id=43308740Issue Tracking
- https://reg.rootedcon.com/cfp/schedule/talk/5Third Party Advisory
- https://www.bleepingcomputer.com/news/security/undocumented-backdoor-found-in-bluetooth-chip-used-by-a-billion-devices/Exploit, Press/Media Coverage
- https://www.bleepingcomputer.com/news/security/undocumented-commands-found-in-bluetooth-chip-used-by-a-billion-devices/Exploit, Press/Media Coverage
- https://www.espressif.com/en/news/Response_ESP32_BluetoothPress/Media Coverage
- https://www.tarlogic.com/news/backdoor-esp32-chip-infect-ot-devices/Third Party Advisory
- https://x.com/pascal_gujer/status/1898442439704158276Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.