is it possible to tamper post data when using frames
https://stackoverflow.com/questions/2015398
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I have a site that is using frames. Is it still possible from the browser for someone to craft post data for one of the frames using the address bar? 2 of the frames are static and the other frame has php pages that communicate using post. And it doesn't appear to be possible but I wanted to be sure.
Solution
No, it is not possible to POST data from the address bar. You can only initiate GET requests from there by adding params to the URL. The POST Body cannot be attached this way.
Regardless of this, it is very much possible to send POST requests to your webserver for the pages in a frame. HTTP is just the protocol with which your browser and webserver talk to each other. HTTP knows nothing about frames or HTML. The page in the frame has a URI, just like any other page. When you click a link, your browser asks the server if it has something for that URI. The server will check if it has something for that URI and respond accordingly. It does not know what it will return though.
With tools like TamperData for Firefox or Fiddler for IE anyone can tinker with HTTP Requests send to your server easily.
OTHER TIPS
Any data in the $_REQUEST array should be considered equally armed and dangerous regardless of the source and/or environment. This includes $_GET, $_POST, and $_COOKIE.
POST data can not be added in the address bar.
You should always check & sanitize all data you get in your PHP code, because anyone could post data to all of your pages.
Don't trust data from outside of your page. Clean it & check it.
Maybe not from the browser, but they can still catch the request (tinker with it) and forward it to the provided destination, with a tool like burp proxy.
To answer your question: No, it is not possible to send post data using the addressbar.
BUT it is possible to send post data to any url in a snap. For example using cURL, or a Firefox extension. So be sure to verify and sanitize all the data you receive no matter if POST or GET or UPDATE or whatever.
This is not iFrame or php specific, so it should be considered in every webapplication. Never ever rely on data send by anyone being correct, valid or secure - especially when send by users.
Yes, they absolutely can, with tools like Firebug, and apparently more specialized tools like the ones listed by Gordon. Additionally, even if they couldn't do it in the browser from your site, they could always create their own form, or submit the post data through scripting or commandline tools.
You absolutely cannot rely on the client for security.
