Vulnerabilities in popular web applications leave thousands of websites, users, and their data prone to exploits and attacks. CVE-2023-49831 is one such vulnerability in the Metagauss User Registration Forms plugin named RegistrationMagic. This plugin, which is widely used in the WordPress ecosystem, allows web administrators to create user registration forms as well as manage users, submissions, and analytics related to these forms. RegistrationMagic versions up to 5.2.3. are affected by the CVE-2023-49831 vulnerability, which could allow an attacker to exploit incorrectly configured access controls and gain unauthorized access to sensitive information. In this post, we will discuss the technical details, exploit information, and relevant documentation.

Vulnerability Overview

The main issue lies with the insufficient authorization checks performed by the plugin, enabling an attacker to gain access to sensitive information. This access can prove to be detrimental when the attacker gets hold of critical user details like email addresses, passwords, and more. When administrators use the RegistrationMagic plugin in their WordPress sites, they risk leaking vital information to potential attackers.

Technical Details

The plugin makes use of various shortcodes to generate forms and retrieve form data such as [RM_Login] for a login form and [RM_Users] to display the registered users list. For example, the [RM_Users] shortcode can display all users' data, including their email addresses and registration date. In the vulnerable versions, the plugin lacks proper authorization checks, meaning that an attacker can simply append the shortcode to any page where it will be executed, and the unauthorized user can then view the registered users' details.

Exploit Details

The attack requires an attacker to create a new page or identify an existing page in a WordPress site using the RegistrationMagic plugin. Next, the attacker appends the [RM_Users] shortcode and publishes the updated page. Finally, navigating to the new or updated page will reveal all registered users' details, such as their email addresses and registration date.

<?php
// Sample exploit code
$header = "From: attacker@example.com" . "\r\n";
$header .= "Subject: CVE-2023-49831 PHP Exploit";
$payload = urlencode('[RM_Users]');
$exploit_url = 'https://www.vulnerable-site.com/wp-admin/post.php?post=PAGEID&action=edit&content='; . $payload;
@mail("attacker@example.com", "", "", $header . $exploit_url);
?>

In the example above, an attacker sends an email to themselves, which would contain a crafted URL that embeds the [RM_Users] shortcode into an existing WordPress page. When clicked, the URL executes the code and adds the list of registered users to the designated target page.

Relevant Documentation and References

1. The official Common Vulnerabilities and Exposures (CVE) entry for CVE-2023-49831 can be found here: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-49831
2. RegistrationMagic WordPress plugin official page: https://wordpress.org/plugins/custom-registration-form-builder-with-submission-manager/
3. Details of the vulnerability on the WPScan vulnerability database: https://wpscan.com/vulnerability/7e6e6724-a79f-434-98a6-9ad58942ac10

Recommendations and Remediation

Administrators who use the RegistrationMagic plugin are advised to update their installations to version 5.2.3.1 or higher immediately. This update has introduced proper authorization checks and mitigates the vulnerability. It is also recommended to restrict access to the WordPress administration dashboard, apply the latest security updates and patches, and regularly review user management settings.

Timeline

Published on: 12/09/2024 13:15:36 UTC