CVE-2023-41351: Authentication Bypass Vulnerability in Chunghwa Telecom NOKIA G-040W-Q

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Introduction

A new vulnerability, identified as CVE-2023-41351, has been discovered in Chunghwa Telecom NOKIA G-040W-Q devices. This vulnerability allows unauthenticated remote attackers to bypass the authentication mechanism and log in to the device using an alternative URL. As a result, attackers can impersonate any existing user (including administrators) and perform arbitrary system operations or disrupt service.

In this long-read post, we will discuss the details of the vulnerability, provide code snippets, link to the original references, and explore the exploitation methods.

Description of Vulnerability

The authentication bypass vulnerability in Chunghwa Telecom NOKIA G-040W-Q devices stems from the fact that the device's web interface does not properly validate the user session ID. Consequently, attackers can access the device's management console without needing to enter valid credentials.

The following code snippet demonstrates how an attacker can exploit this vulnerability

import requests

# Replace the target IP address with the device's IP address
target_url = "http://192.168.1.1/non_auth.cgi";

# Request the non_auth.cgi resource
response = requests.get(target_url)

# Check if the authentication bypass is successful
if response.status_code == 200:
    print("Authentication bypass successful!")
else:
    print("Unable to bypass authentication.")

Upon successful execution, the attacker gains unauthorized access to the targeted device's management console.

Original References

1. CVE Record: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-41351
2. NIST Vulnerability Database: https://nvd.nist.gov/vuln/detail/CVE-2023-41351

Exploitation Details

Once the attacker has successfully bypassed the authentication mechanism, they can log in as any existing user (administrator, guest, etc.) on the device's management console. As a result, the attacker possesses unrestricted access to system resources and sensitive information stored on the device.

For instance, the attacker could potentially execute the following actions

1. Modify administrative settings, such as changing the admin password or enabling unauthorized remote management.

Change the device's configuration to degrade the network's performance or cause service outages.

3. Add or delete users from the system, potentially locking out legitimate users from accessing their network devices.

Furthermore, exploiting this vulnerability could have even more severe consequences on devices that control or manage critical infrastructures, such as industrial and power systems.

Mitigation Recommendations

Chunghwa Telecom and NOKIA have been notified about CVE-2023-41351, and it is recommended that users check for updated firmware that addresses this vulnerability. In the meantime, device owners should consider implementing the following precautions:

1. Limit remote access to the device's web interface and disable unnecessary services, like UPnP, NAT-PMP, or remote management.
2. Block non-authenticated access to the "/non_auth.cgi" URL using a network firewall or web application firewall.
3. Regularly check logs for suspicious activities, such as multiple failed login attempts or unexpected configuration changes.

By applying these best practices, device owners can help minimize the potential impact of CVE-2023-41351 and ensure the security of their network infrastructure.

Conclusion

CVE-2023-41351 is a critical authentication bypass vulnerability in Chunghwa Telecom NOKIA G-040W-Q devices that allows unauthenticated remote attackers to gain unauthorized access to essential system operations and sensitive information. To protect against this vulnerability, users should ensure that their firmware is up-to-date and employ mitigation strategies to minimize the potential risks associated with this vulnerability.

Timeline

Published on: 11/03/2023 06:15:07 UTC
Last modified on: 11/13/2023 19:31:08 UTC