        } elseif ($token->name == 'param') {
            $nest = count($this->currentNesting) - 1;
            if ($nest >= 0 && $this->currentNesting[$nest]->name === 'object') {
                $i = count($this->objectStack) - 1;
                if (!isset($token->attr['name'])) {
                    $token = false;
                    return;
                }
                $n = $token->attr['name'];
                // We need this fix because YouTube doesn't supply a data
                // attribute, which we need if a type is specified. This is
                // *very* Flash specific.
                if (!isset($this->objectStack[$i]->attr['data']) &&
                    ($token->attr['name'] == 'movie' || $token->attr['name'] == 'src')) {
                    $this->objectStack[$i]->attr['data'] = $token->attr['value'];
                }
                // Check if the parameter is the correct value but has not
                // already been added
                if (
                    !isset($this->paramStack[$i][$n]) &&
                    isset($this->addParam[$n]) &&
                    $token->attr['name'] === $this->addParam[$n]
                ) {
                    // keep token, and add to param stack
                    $this->paramStack[$i][$n] = true;
                } elseif (isset($this->allowedParam[$n])) {
                    // keep token, don't do anything to it
                    // (could possibly check for duplicates here)
                } else {
                    $token = false;
                }
            } else {
                // not directly inside an object, DENY!
                $token = false;
            }
        }
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.