Vulnerability Description
Espressif ESP32 chips allow 29 hidden HCI commands, such as 0xFC02 (Write memory).
CVSS Score
6.8
MEDIUM
CVSS:3.1/AV:P/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:L
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Espressif | Esp32 Firmware | - |
| Espressif | Esp32 | - |
Related Weaknesses (CWE)
References
- https://cheriot.org/auditing/backdoor/2025/03/09/no-esp32-style-backdoor.htmlTechnical DescriptionThird Party Advisory
- https://darkmentor.com/blog/esp32_non-backdoor/ExploitTechnical DescriptionThird Party Advisory
- https://flyingpenguin.com/?p=67838Technical DescriptionThird Party Advisory
- https://github.com/TarlogicSecurity/Talks/blob/main/2025_RootedCon_BluetoothToolThird 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-blExploitPress/Media Coverage
- https://www.bleepingcomputer.com/news/security/undocumented-commands-found-in-blExploitPress/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
FAQ
What is CVE-2025-27840?
CVE-2025-27840 is a vulnerability with a CVSS score of 6.8 (MEDIUM). Espressif ESP32 chips allow 29 hidden HCI commands, such as 0xFC02 (Write memory).
How severe is CVE-2025-27840?
CVE-2025-27840 has been rated MEDIUM with a CVSS base score of 6.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-27840?
Check the references section above for vendor advisories and patch information. Affected products include: Espressif Esp32 Firmware, Espressif Esp32.