Header Security Question

[spfoonnewb]

Are there security risks with the following code? (Injection etc) If so what should I be filtering? Since the URL has to be the header location I figure there wouldn't?

[code]<?php

ob_start();

$url = $_GET["url"];

if (isset($url)) {

header("Location: $url");

}

else {
}
?>[/code]

[trq]

[quote]Are there security risks with the following code?[/quote]

Not really. You should code it like this however to stop notices.

[code=php:0]
if (isset($_GET['url'])) {
[/code]