    public function filter(&$uri, $config, $context) {
        foreach($this->blacklist as $blacklisted_host_fragment) {
            if (strpos($uri->host, $blacklisted_host_fragment) !== false) {
                return false;
            }
        }
        return true;
    }
The software does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.