CVE-2022-3829 - Stored Cross-Site Scripting Vulnerability in Font Awesome 4 Menus WordPress Plugin

CVE-2022-3829 is a newly discovered vulnerability in the popular WordPress plugin, Font Awesome 4 Menus, which allows high privileged users such as admin to perform Stored Cross-Site Scripting (XSS) attacks, even when the unfiltered_html capability is disallowed (e.g., in a multisite setup). This vulnerability affects version 4.7. and previous versions of the plugin.

This long read post will discuss the details of the vulnerability, a code snippet showcasing the issue in the plugin's source code, and links to original references of the issue. We will also cover the potential risks and possible mitigations for this vulnerability.

Exploit Details

The vulnerability exists in the plugin's handling of its settings. It does not sanitize and escape some of the settings before storing them, allowing an attacker to create XSS payloads that could be triggered when the user visits a page containing the maliciously crafted settings.

The following code snippet demonstrates the vulnerable code located in the file /fa4_submenu_metabox.php of the plugin, where the $instance variable is used to hold the plugin's settings without proper sanitation:

<?php
add_filter( 'wp_setup_nav_menu_item', 'fa4_setup_nav_menu_item' );
function fa4_setup_nav_menu_item( $item ) {
    if ( ! isset( $item->object_id ) || ! $item->object_id ) {
        return $item;
    }

    $instance = get_post_meta( $item->object_id, '_fa4_submenu', true );
    // ... some code
    echo $instance['content'];
?>

By exploiting this vulnerability, an attacker could potentially steal sensitive information, deface website content, or redirect users to malicious websites, among other possible impacts.

Original References

1. CVE-2022-3829 - NVD
2. NVD Data Feed - CVE-2022-3829

Potential Risks

Given that the Font Awesome 4 Menus WordPress plugin is widely used, this vulnerability presents a considerable risk for WordPress users, especially those operating multisite setups. Admin users exploiting this vulnerability can have a significant impact on the website's security, potentially affecting its users and even damaging its reputation.

The following steps can be taken to mitigate the risks associated with CVE-2022-3829

1. Update the Font Awesome 4 Menus WordPress plugin to the latest version, which addresses the vulnerability.
2. In the meantime, restrict access to plugin settings only to trusted administrators to reduce the possibility of exploitation.
3. Regularly monitor for any suspicious activity on your website's backend, such as an increase in failed login attempts or unauthorized changes to your site's content.

Conclusion

It is crucial to keep plugins updated and be aware of potential security issues that may arise. CVE-2022-3829 highlights the importance of properly sanitizing and escaping user-input data in plugin settings, even when only high-privileged users are involved.

By becoming familiar with this vulnerability's details, plugin developers can avoid similar issues in the future, while WordPress site owners can take proactive steps to protect their websites and users.

Timeline

Published on: 01/16/2024 16:15:10 UTC
Last modified on: 01/23/2024 14:01:44 UTC