View file wu-engine/wu-actions/captcha.php

<?php
session_start();
$aResponse['error'] = false;
if(isset($_POST['action']) && isset($_POST['qaptcha_key']))
{
$_SESSION['qaptcha_key'] = false;	
if(htmlentities($_POST['action'], ENT_QUOTES, 'UTF-8') == 'qaptcha')
{
$_SESSION['qaptcha_key'] = $_POST['qaptcha_key'];
echo json_encode($aResponse);
}
else
{
$aResponse['error'] = true;
echo json_encode($aResponse);
}
}
else
{
$aResponse['error'] = true;
echo json_encode($aResponse);
}