Description:
------------
After typecasting an object to an array you can iterate over the properties and manipulate private/protected properties.

Reproduce code:
---------------
<?php

class Foobar {
    private $oObject;
    public function __construct() {
        $this->oObject = new stdClass;
    }
}

$oFoobar = new Foobar;
$aProperties = (array)$oFoobar;
foreach ($aProperties as $mProperty) {
    if (is_object($mProperty) && ($mProperty instanceof stdClass)) {
        $mProperty->blaaa = 'fooo';
    }
}
var_dump($oFoobar);

?>

Expected result:
----------------
error because you must not access and rewrite/manipulate private/protected properties.

Actual result:
--------------
object(Foobar)#1 (1) {
  ["oObject:private"]=>
  object(stdClass)#2 (1) {
    ["blaaa"]=>
    string(4) "fooo"
  }
}