php通过session防url攻击方法

<?php
session_start(); 
$clean = array(); 
$email_pattern = '/^[^@s<&>]+@([-a-z0-9]+.)+[a-z]{2,}$/i'; 
if (preg_match($email_pattern, $_POST['email'])) 
{
$clean['email'] = $_POST['email']; 
$user = $_SESSION['user']; 
$new_password = md5(uniqid(rand(), TRUE)); 
if ($_SESSION['verified']) 
{ 
/ Update Password / 
mail($clean['email'], 'Your New Password', $new_password); 
} 
} 
?>