CVE-2025-27840-WIP

A Work-In-Progress for CVE-2025-27840

CVE-2025-27840 Overview

CVE-2025-27840 is a medium-severity vulnerability (CVSS 6.8) affecting Espressif ESP32 Bluetooth chips, which are integrated into over 1 billion IoT devices globally. The flaw involves 29 undocumented Host Controller Interface (HCI) commands that could enable unauthorized memory access and device control.

🔧 Key Technical Details

• Affects ESP32 firmware version 2025-03-06
• Critical command 0xFC02 allows direct memory writing
• Requires physical access or privileged rights for exploitation

⚠️ Potential Risks

• Device spoofing and unauthorized data access
• Network pivoting and persistent threats
• Potential compromise of medical devices, smart locks, and industrial systems

🛡️ Mitigation Status

• Espressif disputes backdoor claims but plans to remove undocumented commands in future updates
• Proof-of-concept exploit code exists, though active exploitation remains unconfirmed
• For detection, SOC Prime offers threat rules compatible with 40+ security platforms
• Organizations should monitor for patches and restrict physical access to vulnerable devices

Note: While initially reported as a backdoor, Espressif clarified that exploitation requires privileged access, reducing immediate risk.