Is it safe to process code within the same page?

[bluebird]

Hi,

I have heard it was unsafe to redirect users to the same page while having code processed at the top of the page's code.
For instance, with a form, the action url would be empty and the user's data processed at the top of the same page. If that is unsafe, then I should create another page to process the output.

Thanks in advance!

[bowersbros]

Where did you hear that was unsafe?

As long as you did proper checks for if the data has been sent and then proper validation as far as i'm aware, its the same.

[jacek]

It should not make a difference where the processing is done, it's the actual processing that may open up a vulnerability.