CVE-2021-4074 : Exploit Details and Defense Strategies

A Stored Cross-Site Scripting vulnerability exists in the WHMCS Bridge WordPress plugin versions up to and including 6.1, allowing attackers to inject malicious scripts through the cc_whmcs_bridge_url parameter.

Understanding CVE-2021-4074

This CVE involves a security flaw in the WHMCS Bridge WordPress plugin that enables Stored Cross-Site Scripting attacks, potentially impacting systems using versions up to 6.1.

What is CVE-2021-4074?

The vulnerability in the WHMCS Bridge WordPress plugin allows unauthorized users to inject arbitrary web scripts due to missing authorization checks on the cc_whmcs_bridge_add_admin function.

The Impact of CVE-2021-4074

Low-level authenticated users such as subscribers can exploit this vulnerability, potentially leading to unauthorized script injections and other malicious activities.

Technical Details of CVE-2021-4074

This section provides insights into the vulnerability specifics.

Vulnerability Description

The vulnerability allows attackers to perform Stored Cross-Site Scripting attacks using the cc_whmcs_bridge_url parameter in the bridge_cp.php file.

Affected Systems and Versions

WHMCS Bridge versions up to and including 6.1 are affected by this vulnerability.

Exploitation Mechanism

Attackers can exploit this issue by injecting malicious scripts through the vulnerable cc_whmcs_bridge_url parameter.

Mitigation and Prevention

To address CVE-2021-4074, certain steps need to be taken for mitigation and prevention.

Immediate Steps to Take

Users are advised to update the WHMCS Bridge plugin to version 6.3 or a newer release to mitigate the risk of exploitation.

Long-Term Security Practices

Implementing proper input validation and authorization checks within the plugin can help prevent similar vulnerabilities in the future.

Patching and Updates

Regularly updating the WHMCS Bridge plugin to the latest version is essential to protect systems from known vulnerabilities.