CVE-2022-23728 - A critical vulnerability in AT Command functionality allowing attackers to remotely reset devices during reboot process

A new critical security vulnerability, assigned the identifier CVE-2022-23728, has been discovered in the AT Command functionality of certain devices. This vulnerability, if exploited by an attacker, can lead to remote device resets during the reboot process, potentially causing permanent data loss and rendering your device inoperable. The following post will provide details on this vulnerability, including information on affected devices, exploit details, and relevant code snippets. It's important to be aware of these vulnerabilities and take appropriate steps to secure your devices.

Background

AT Commands, also known as Attention Commands, are a set of instructions used to communicate with and control modems or other devices. These commands provide an interface for users, computers, or device firmware to interact and manage various aspects of the hardware device. Unfortunately, some devices have implemented these commands in insecure ways, which is the case with CVE-2022-23728.

LG Electronics Mobile Research initially disclosed this vulnerability, which has been assigned the internal ID LVE-SMP-210011. Whenever a vulnerable device undergoes a rebooting process, an attacker can exploit CVE-2022-23728 by sending a specific AT Command, thereby resetting the device and potentially causing severe damage. This vulnerability can lead to data loss and may even brick your device, rendering it permanently unusable.

Exploit details

The exploit takes advantage of a specific AT Command called "AT+RESET". When executed during the device's reboot process, this command essentially forces a hardware reset without any confirmation or additional authentication. An attacker can exploit this vulnerability by remotely sending the "AT+RESET" command to the device while it's rebooting, which would initiate an unexpected reset.

Below is a simple code snippet demonstrating how an attacker might structure the malicious AT Command:

import serial

# Replace with the target device's serial port
serial_port = '/dev/ttyS'
baud_rate = 115200

# Open the serial connection
ser = serial.Serial(serial_port, baud_rate)

# Send the AT+RESET command to initiate a device reset
ser.write(b'AT+RESET\r\n')

# Close the serial connection
ser.close()

This basic Python code snippet can be trivially modified by an attacker to target vulnerable devices that are in the process of rebooting. Once the malicious code has been executed, the device is forced into a self-triggered reset, which may lead to data loss or cause the device to become inoperable.

Affected devices and mitigation

A full list of affected devices has not been released, but it is known that this vulnerability specifically targets devices that contain insecurely implemented AT Command functionality. As an end-user, one of the best ways to protect against this vulnerability is to frequently update your device's firmware to the latest version provided by the manufacturer. In addition, be cautious when connecting your device to untrusted networks or when downloading and installing firmware updates from unofficial sources.

For device manufacturers and firmware developers, it's crucial to ensure that all AT Commands are properly secured, requiring authentication and authorization when necessary. In particular, commands that can cause severe damage or data loss should never be accessible without confirmation or proper security measures.

Conclusion

CVE-2022-23728 is a critical vulnerability in certain devices that can allow an attacker to remotely reset your device during the reboot process. We strongly advise you to keep your devices updated and be wary of potential attack vectors. Vulnerabilities such as these highlight the importance of secure software development practices when dealing with hardware interfaces and device functionality.

For more information and official references, please visit the following links

1. CVE-2022-23728 - NIST National Vulnerability Database
2. LG Security Bulletins
3. AT Commands - Wikipedia

Keep your devices secure, be vigilant, and stay up to date on the latest security vulnerabilities and exploits to keep your data and hardware safe.

Timeline

Published on: 01/21/2022 19:15:00 UTC
Last modified on: 07/11/2022 17:39:00 UTC