A recent security advisory has disclosed a Reflected Cross-Site Scripting (XSS) vulnerability in the Rock Convert WordPress plugin prior to version 2.11.. The vulnerability was assigned CVE-2022-3440, and it is due to insufficient input sanitation and output escaping of URL parameters used within specific Rock Convert widget. In this post, we will delve deeper into the details of this vulnerability, provide steps to reproduce the issue, and share advice on how to mitigate the risk.

Vulnerability Overview

The Rock Convert WordPress plugin (https://wordpress.org/plugins/rock-convert/) is a content editing tool designed to optimize the writing process and improve the SEO ranking of a WordPress website. However, before version 2.11., the plugin does not properly sanitise and escape an URL attribute when a specific Rock Convert widget, like sharing buttons, is present on a page. This leads to a Reflected Cross-Site Scripting (XSS) vulnerability that could allow an attacker to execute arbitrary JavaScript code within the context of the current user's browser session.

Relevant Code Snippet

The vulnerability is located in the rock-convert-plugin.php file, where the plugin processes URL parameters without properly sanitising and escaping the input:

function rock_convert_widget() {
    // ...

    $widget_url = $_GET['url'];
    
    // ...
    
    echo '<div class="rock-convert-widget" data-url="' . $widget_url . '"></div>';
}

As the code snippet demonstrates, the widget_url variable is populated with input from the user-supplied $_GET['url'] parameter without any sanitisation and is then directly used within the output without properly escaping. This lack of proper input validation and escaping creates the Reflected XSS vulnerability.

Exploit Details & Proof of Concept (PoC)

To exploit the vulnerability, an attacker can craft a malicious URL that includes an XSS payload. When a victim visits the malicious URL, the payload is executed in the context of the victim's browser session.

An example of a malicious URL exploiting the vulnerability

https://victim-website.com/?url="><script>alert('XSS!')</script>;

In this example, the <script> tag containing the alert('XSS!') payload is injected into the URL parameter. The injection is rendered correctly in the victim's browser, leading to the execution of the arbitrary JavaScript code.

Mitigation & Remediation

Immediately update the Rock Convert WordPress plugin to the latest version (2.11. or higher), which addresses the vulnerability. The update can be found on the plugin's official WordPress page: https://wordpress.org/plugins/rock-convert/.

Developers should always ensure proper input validation, escaping, and sanitisation, especially when dealing with user-supplied data in URL parameters. A good reference guide is available on the OWASP website: https://www.owasp.org/index.php/Data_Validation

Conclusion

CVE-2022-3440 is a Reflected Cross-Site Scripting vulnerability in the Rock Convert WordPress plugin (versions prior to 2.11.). The issue results from inadequate input sanitisation and escaping of URL attributes in specific plugin widgets. Timely updating the Rock Convert WordPress plugin and following secure coding practices are essential steps to protect your website and its users from potential cyber threats.

Timeline

Published on: 10/31/2022 16:15:00 UTC
Last modified on: 11/01/2022 13:51:00 UTC