csnyder wrote:
Right, you can't trust the referer if you fear scripted attacks.

John, is that what you were talking about, or was it something more
abstract and seo-related?

I was picturing people using the open redirect to take advantage of
your page rank by causing your site to link to theirs.


Your paranoia is well justified. Open redirects are exploited by unsavory people in a number of ways. I came across a phishing email recently posing as a fake "Paypal confirmation". In the page was a link which appeared to point at aol.com (some 1/2 internet savvy people glance at the url to see if it points to a "reputable" site before clicking away on it). The aol.com link led to a well constructed imitation of the Paypal login page which was intended to maliciously steal accounts. Here is an example of the link:

http://www.aol.com/redir.adp?_e_t=ap&_a_v=2.0&_a_i=100124311x1116601028x1077500809&_url=http://www.nyphp.org

If you want to peek at a copy of the original phishing mail, check out http://www.datawhorehouse.com/0day/paypalphish

The safer thing for Susan to do would probably be to put all the valid redirect URL's in an array like:

redir.php:

<?php
$validURLS=array('
   0=>'www.mysite.com',
   1=>'www.yahoo.com',
   2=>'www.nyphp.org',
   3=>'www.php.net'
);

// some code to store hit in db logs goes here

header('Location: http://'.intval($_GET['r']));
?>

~Rolan



~Rolan
_______________________________________________
New York PHP Community Talk Mailing List
http://lists.nyphp.org/mailman/listinfo/talk

NYPHPCon 2006 Presentations Online
http://www.nyphpcon.com

Show Your Participation in New York PHP
http://www.nyphp.org/show_participation.php

Reply via email to