CVE-2025-27840

MEDIUM

Published Mar 8, 2025 Modified Mar 12, 2025 CWE-912

Description

Espressif ESP32 chips allow 29 hidden HCI commands, such as 0xFC02 (Write memory).

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CVSS v3.1 Score

6.8

MEDIUM

CVSS:3.1/AV:P/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:L

Weakness Type (CWE)

CWE-912 CWE-912

Affected Products

Vendor	Product	Versions
espressif	esp32_firmware	All
espressif	esp32	All

References

Exploits

https://darkmentor.com/blog/esp32_non-backdoor/ https://www.bleepingcomputer.com/news/security/undocumented-backdoor-found-in-bluetooth-chip-used-by-a-billion-devices/ https://www.bleepingcomputer.com/news/security/undocumented-commands-found-in-bluetooth-chip-used-by-a-billion-devices/

Other References

https://cheriot.org/auditing/backdoor/2025/03/09/no-esp32-style-backdoor.html https://flyingpenguin.com/?p=67838 https://github.com/TarlogicSecurity/Talks/blob/main/2025_RootedCon_BluetoothTools.pdf https://github.com/em0gi/CVE-2025-27840 https://github.com/esphome/esphome/discussions/8382 https://github.com/orgs/espruino/discussions/7699 https://news.ycombinator.com/item?id=43301369 https://news.ycombinator.com/item?id=43308740 https://reg.rootedcon.com/cfp/schedule/talk/5 https://www.espressif.com/en/news/Response_ESP32_Bluetooth

Frequently Asked Questions

What is CVE-2025-27840? +

Espressif ESP32 chips allow 29 hidden HCI commands, such as 0xFC02 (Write memory). It has a CVSS v3.1 base score of 6.8 (MEDIUM).

How severe is CVE-2025-27840? +

CVE-2025-27840 has a CVSS v3.1 score of 6.8 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2025-27840? +

CVE-2025-27840 affects products from espressif, specifically: esp32, esp32_firmware. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-27840? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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Quick Facts

CVSS Score: 6.8
Severity: MEDIUM
Published: Mar 8, 2025

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