Vulnerability in Espressif Esp32
CVE-2025-27840
Espressif ESP32 chips allow 29 hidden HCI commands, such as 0xFC02 (Write memory).
EPSS: 0.006 (68.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:P/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:L.
Affected products
- Espressif Esp32 — versions 2025-03-06
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/TarlogicSecurity/Talks/blob/main/2025_RootedCon_BluetoothTools.pdf
- x.com/pascal_gujer/status/1898442439704158276
- www.tarlogic.com/news/backdoor-esp32-chip-infect-ot-devices/
- www.bleepingcomputer.com/news/security/undocumented-backdoor-found-in-bluetooth…
- reg.rootedcon.com/cfp/schedule/talk/5
- flyingpenguin.com/
- github.com/em0gi/CVE-2025-27840
- github.com/orgs/espruino/discussions/7699
- www.bleepingcomputer.com/news/security/undocumented-commands-found-in-bluetooth…
- darkmentor.com/blog/esp32_non-backdoor/
Frequently asked questions
- What is CVE-2025-27840?
- CVE-2025-27840 is a medium-severity vulnerability in Espressif Esp32, classified under Hidden Functionality. CVSS score: 6.8/10. Published 2025-03-08.
- How severe is CVE-2025-27840?
- Medium severity. CVSS v3 base score is 6.8 out of 10.
- Is CVE-2025-27840 known to be exploited?
- 19 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.