01 Record
CVE-2025-27840
Espressif ESP32 chips allow 29 hidden HCI commands, such as 0xFC02 (Write memory).
MediumPUBLISHEDCNA: mitre
CNA base score6.8 CVSS v3.xCVSS:3.1/AV:P/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:L
02 Description
Espressif ESP32 chips allow 29 hidden HCI commands, such as 0xFC02 (Write memory).
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 1.35% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 71.1% of scored records. A rank, not a probability.
- NVD base score
- 6.8 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:P/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N
- NVD analysis status
- Analyzed. NVD last modified this record on 2026-06-17.
- Red Hat severity
- No Red Hat rating. Red Hat rates the CVEs that affect its products.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2025-03-08 00:00Z1 YR AGO
- Last updated
- 2025-05-12 15:33Z1 YR AGO
- Reserved
- 2025-03-08
- Assigning CNA
- mitre
- Record state
- PUBLISHED
- Severity
- Medium (CVSS 6.8)
- CNA CVSS vector
- CVSS:3.1/AV:P/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:L
- Weaknesses
- CWE-912Hidden FunctionalityClass
- Data version
- 5.1
- Document digest
- b876169ca111ac1a64b8534b77e062ee9deb2f8cf609e9b2929282be7aecb9ed
05 Affected products
VendorProductVersionsPlatforms
06 References
- github.comhttps://github.com/TarlogicSecurity/Talks/blob/main/2025_RootedCon_BluetoothTools.pdf
- x.comhttps://x.com/pascal_gujer/status/1898442439704158276
- www.tarlogic.comhttps://www.tarlogic.com/news/backdoor-esp32-chip-infect-ot-devices/
- www.bleepingcomputer.comhttps://www.bleepingcomputer.com/news/security/undocumented-backdoor-found-in-bluetooth-chip-used-by-a-billion-devices/
- reg.rootedcon.comhttps://reg.rootedcon.com/cfp/schedule/talk/5
- flyingpenguin.comhttps://flyingpenguin.com/?p=67838
- github.comhttps://github.com/em0gi/CVE-2025-27840
- github.comhttps://github.com/orgs/espruino/discussions/7699
- www.bleepingcomputer.comhttps://www.bleepingcomputer.com/news/security/undocumented-commands-found-in-bluetooth-chip-used-by-a-billion-devices/
- darkmentor.comhttps://darkmentor.com/blog/esp32_non-backdoor/
- news.ycombinator.comhttps://news.ycombinator.com/item?id=43308740
- news.ycombinator.comhttps://news.ycombinator.com/item?id=43301369
- github.comhttps://github.com/esphome/esphome/discussions/8382
- cheriot.orghttps://cheriot.org/auditing/backdoor/2025/03/09/no-esp32-style-backdoor.html
- www.espressif.comhttps://www.espressif.com/en/news/Response_ESP32_Bluetooth