Cyber Posture

CVE-2025-66409

Critical

Published: 02 December 2025

Published
02 December 2025
Modified
13 February 2026
KEV Added
Patch
CVSS Score 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
EPSS Score 0.0005 13.9th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Description

Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.

Security Summary

CVE-2025-66409 is an out-of-bounds read vulnerability (CWE-125) in the Espressif IoT Development Framework (ESF-IDF), affecting versions 5.5.1, 5.4.3, 5.3.4, 5.2.6, 5.1.6, and earlier. The issue resides in the Bluetooth stack on ESP32 devices when AVRCP is enabled. It occurs when the stack processes a malformed VENDOR DEPENDENT command from a peer device, accessing memory before validating the command buffer length. This flaw carries a CVSS v3.1 base score of 9.1 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H), indicating critical severity due to high impacts on confidentiality and availability.

An attacker within Bluetooth range can exploit this vulnerability remotely without privileges or user interaction by sending a specially crafted VENDOR DEPENDENT command to a vulnerable ESP32 device with AVRCP enabled. Successful exploitation triggers an out-of-bounds read, potentially leaking sensitive memory contents or inducing unexpected behavior such as crashes or denial of service.

Mitigation requires updating to a patched version of ESF-IDF, as evidenced by fixes in the Espressif esp-idf repository. Relevant commits include 075ed218cadb8088155521cd8a795d8a626519fb, 2f788e59ee361eee230879ae2ec9cf5c893fe372, 798029129a71c802cff0e75eb59f902bca8f1946, 999710fccf95ae128fe51b5679d6b7c75c50d902, and d5db5f60fc1dcfdd8cd3ee898fdefaa272988ace, which address the buffer length validation in the Bluetooth AVRCP handling.

Details

CWE(s)
CWE-125

Affected Products

espressif
esp-idf
≤ 5.1.6 · 5.2 — 5.2.6 · 5.3 — 5.3.4

MITRE ATT&CK Enterprise Techniques

T1011.001 Exfiltration Over Bluetooth Exfiltration
Adversaries may attempt to exfiltrate data over Bluetooth rather than the command and control channel.
T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

Out-of-bounds read enables memory leak (exfiltration over Bluetooth) and crash (endpoint DoS via application exploitation).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

References