Tuesday, March 03, 2009

URLs for 10 minutes

Protect Your Site With URL Rewriting seems a little bit of a mad suggestion. They are basically suggesting that you change your application's URIs every 10 minutes to prevent XSS and XSRF (Cross Site Request Forging).

We could mitigate much of the risk of these vulnerabilities by frequently changing our URLs—not once every 200 years but once every 10 minutes. Attackers would no longer be able to exploit application vulnerabilities by mass e-mailing poisoned hyperlinks because the links would be broken and invalid by the time the messages reached their intended victims. With all due respect to Sir Tim, while "cool" URIs may not change, secure ones certainly do.


The negatives seem vast and I wonder what this is really trying to solve, as they say at the end:
An automatically expiring URL can still be exploited by an attacker with access to a Web server of his own. Instead of sending out malicious hyperlinks that point directly to the vulnerable page, he can send out hyperlinks that point to his own site. When his site gets a hit from one of the phished e-mails, it can contact a landing page on the vulnerable site to obtain a valid time stamp and then redirect the user accordingly.


If you are a REST advocate then maybe a quick read over, The Resource-Oriented Architecture in Action, may soothe you (from the excellent book, RESTful Web Services).

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