CVE-2021-4226 Explained : Impact and Mitigation

RSFirewall < 1.1.25 - IP Block Bypass is a vulnerability that allows for authorization bypass through user-controlled key in RSFirewall! plugin versions less than 1.1.25.

Understanding CVE-2021-4226

This CVE involves a security flaw in the RSFirewall! plugin that enables unauthorized access by bypassing IP blocking mechanisms.

What is CVE-2021-4226?

RSFirewall! plugin versions prior to 1.1.25 are prone to an authorization bypass vulnerability, which allows attackers to evade IP blocking measures by manipulating user-controlled keys.

The Impact of CVE-2021-4226

Exploitation of this vulnerability could lead to unauthorized access to websites utilizing the RSFirewall! plugin, potentially compromising sensitive data and security.

Technical Details of CVE-2021-4226

This section outlines the core technical aspects of the vulnerability.

Vulnerability Description

RSFirewall! attempts to detect the original IP address by analyzing various HTTP headers, presenting a loophole that can be exploited due to its implementation.

Affected Systems and Versions

The RSFirewall! plugin versions below 1.1.25 are affected by this vulnerability, especially for installations where default configurations are retained.

Exploitation Mechanism

Attackers can exploit this flaw by manipulating user-controlled keys to bypass IP blocking mechanisms and gain unauthorized access to websites.

Mitigation and Prevention

To address CVE-2021-4226 and enhance security, follow the recommended mitigation strategies below.

Immediate Steps to Take

Update the RSFirewall! plugin to version 1.1.25 or later to mitigate the vulnerability.
Implement additional access control measures to complement IP blocking functionalities.

Long-Term Security Practices

Regularly monitor and audit access logs for any suspicious activities indicating unauthorized access attempts.
Stay informed about security updates and best practices to enhance the overall security posture of your web applications.

Patching and Updates

Apply timely security patches and updates provided by RSFirewall! to ensure protection against known vulnerabilities and security loopholes.