CVE-2025-27840 Overview
Espressif ESP32 chips allow 29 hidden HCI commands, such as 0xFC02 (Write memory).
Critical Impact
The undocumented HCI commands could allow unauthorized memory operations, leading to potential compromise of device integrity and confidentiality. This makes the vulnerability crucial to address in environments leveraging ESP32 for critical operations.
Affected Products
- espressif esp32_firmware
- espressif esp32
Discovery Timeline
- 2025-03-08 - CVE CVE-2025-27840 published to NVD
- 2025-03-12 - Last updated in NVD database
Technical Details for CVE-2025-27840
Vulnerability Analysis
The vulnerability occurs due to 29 undocumented HCI Bluetooth commands that can manipulate device memory. This includes command 0xFC02, which allows unauthorized memory writing, exposing devices to potential data corruption or unauthorized code execution.
Root Cause
The root cause is the inclusion of undocumented HCI commands within the ESP32 firmware that bypass typical security restrictions, allowing low-level memory manipulation.
Attack Vector
Physical access is required to exploit these hidden HCI commands.
// Example pseudo code for memory writing command
void exploitCommand()
{
int hciCommand = 0xFC02; // Write memory command
int memoryAddress = 0x12345678;
int data = 0xDEADBEEF; // Example data
executeHCICommand(hciCommand, memoryAddress, data);
}
Detection Methods for CVE-2025-27840
Indicators of Compromise
- Unusual memory access logs
- Unauthorized Bluetooth HCI command execution traces
- Unexpected firmware behavior or crashes
Detection Strategies
Leveraging behavioral analysis tools to track Bluetooth communication and using anomaly detection algorithms to identify undocumented HCI command executions.
Monitoring Recommendations
Regularly monitor logs for exotic HCI commands and set alerts for any use of command 0xFC02 and related undocumented actions. Integrate SentinalOne’s AI-driven detection to flag suspicious behaviors indicative of attempted exploitations.
How to Mitigate CVE-2025-27840
Immediate Actions Required
- Disable undocumented HCI commands by applying vendor patches
- Restrict physical access to devices
- Regularly update to the latest firmware
Patch Information
Espressif has not released an official patch yet. It is advised to check ESP32's vendor advisory channels for future updates.
Workarounds
Consider implementing strict access controls and monitoring Bluetooth traffic to detect anomalous command usage.
# Example configuration to disable HCI commands
hci-tools disable 0xFC02
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
