Espressif ESP32 chips allow 29 hidden HCI commands, such as 0xFC02 (Write memory).
Priority LOW 33CWE-912Published · Updated
Key facts
- Attack vector
- Physical
- Privileges required
- High
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · Low
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
Espressif ESP32 chips allow 29 hidden HCI commands, such as 0xFC02 (Write memory).
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01356 71st percentileScored 2026-11-07
Public exploit Yes 3 exploit referencesTagged by NVD
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| espressif | ESP32 | 2025-03-06 | — | No fix listed | CNA |
- ESP32 Vendorespressif Affected 2025-03-06 Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2025-27840
- 2026-10-03 Alias added: GHSA-jfwf-rfmg-7f8m
References
Exploit 3
Advisory 6
- https://github.com/TarlogicSecurity/Talks/blob/main/2025_RootedCon_BluetoothTools.pdf
- 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://flyingpenguin.com/?p=67838
- https://cheriot.org/auditing/backdoor/2025/03/09/no-esp32-style-backdoor.html
More espressif Esp32 Firmware vulnerabilities
- TI-2021-13298 An attacker can cause a Denial of Service and kernel panic in v4.2 and earlier versions… CVSS 3.1HIGH 7.5
Sources
- CVE-2025-27840 · CVE Program
- CVE-2025-27840 · NVD
- FIRST EPSS
- GHSA-jfwf-rfmg-7f8m · GitHub Advisory Database · CC BY 4.0
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