[nycphp-talk] session validation between http requests

John Campbell jcampbell1 at
Sat Aug 1 22:02:55 EDT 2009

On Sat, Aug 1, 2009 at 3:35 AM, Konstantin Rozinov<krozinov at> wrote:

> Any ideas, comments, or suggestions would be greatly welcomed!

For improved security, you should not do:

>        header('Location: /logout');

but rather invalidate the session right there.  Your code relies on
the attacker actually following redirects to unset the session.
People who hijack sessions don't follow redirects.

I did a test to see if this would actually be valuable, and from my
access log file the most common user agent only had 3% of the traffic,
so I think there is some value to this approach.  I think 'httponly'
cookies is probably a better XSS attack mitigation strategy in the
long run (though there is no reason you can't do both).

In php 5.2+ the option is:
ini_set("session.cookie_httponly", 1);

It is supported by FF 3+, IE7+, and Safari 4+

John Campbell

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