The Common Vulnerabilities and Exposures (CVE) system continues to expose various security issues affecting various systems and software. One such vulnerability, identified as CVE-2022-3689, is found in the HTML Forms WordPress plugin before 1.3.25, which allows high-privileged users to exploit a SQL injection and compromise the security of the website running it.

In this in-depth analysis, we'll dive into the core of the issue, provide essential code snippets, consult original references, and detail the specifics of the exploit.

The Vulnerability

The core of this vulnerability lies in how the HTML Forms plugin is handling user inputs before passing them to SQL queries. As it turns out, the plugin does not properly escape a specific parameter before using it in a SQL statement, opening up the possibility of a successful SQL injection attack. High privileged users, like administrators or editors, can use this vulnerability to execute arbitrary SQL queries and potentially gain unauthorized access to sensitive data, modify the website's content, or even hijack the entire site.

Exploring the Code

To understand the issue and how it can be exploited, let's first examine a critical code snippet from the vulnerable HTML Forms plugin:

function hf_get_form($form_id) {
    global $wpdb;
    $table_name = $wpdb->prefix . 'htmlforms';
    $sql = $wpdb->prepare("SELECT * FROM {$table_name} WHERE id = %d", $form_id);
    $form = $wpdb->get_row($sql, OBJECT);
    return $form;
}

In this function, the $wpdb->prepare() method is used to create the SQL query string, with the $form_id parameter being integrated directly into the query. The issue, as previously stated, stems from a failure to properly escape the $form_id parameter. This oversight presents an opportunity for an attacker to inject malicious SQL code and execute it on the server.

Exploit Details

While the plugin is designed to serve high privileged users, like administrators or editors, this same authorized group can leverage the plugin's vulnerability. By injecting a crafted SQL query into the vulnerable $form_id parameter, attackers can retrieve sensitive data, delete or modify content, or even escalate their privileges.

For instance, suppose an attacker submits the following crafted input as the $form_id value

1; DROP TABLE wp_users; --

Drop the wp_users table.

As a result, all user data from the WordPress site may be lost or compromised.

Mitigation

Fortunately, the issue has been addressed in the HTML Forms plugin version 1.3.25. Therefore, it is highly recommended that you update your plugin to the latest version. Additionally, regular updates, audits, and penetration testing should be part of your WordPress site's security routine to ensure the safety of your site and its users.

For further information on this vulnerability, please consult the following sources

- CVE-2022-3689
- HTML Forms Changelog

In Summary

The CVE-2022-3689 vulnerability in the HTML Forms WordPress plugin (before version 1.3.25) presents a significant security risk due to improper escaping of a parameter used in SQL queries. This oversight enables high privileged users to perform SQL injection attacks, compromise sensitive data, and more. Updating your HTML Forms plugin to version 1.3.25 or newer is the key to mitigating this vulnerability and securing your website.

Timeline

Published on: 11/28/2022 14:15:00 UTC
Last modified on: 11/30/2022 03:45:00 UTC