is it possible to tamper post data when using frames - php

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.

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.

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.

Related

redirect to a page on a different server and post parameters to it

I am supposed to capture data from a form and send the data to a url on a different server.For eg:-I have a form on a page at the url http://www.form.com/register.php.
I capture all the data from this form and for some reason need this data to be processed on a page on another server at http://www.thereceivingpage.com/process.php.
As of now I am using headers to redirect with the parameters in the query string something like this:-Header(Location:http://www.thereceivingpage.com/process.php?name=alice&address=a1&address2=a2) but I need to send a larger amount of data which wont happen as GET request. Can anyone suggest a better way where in I can post data rather than the data in the query string ...thanks
Use cURL. If you have to redirect to the site, it gets a bit trickier but you can still do it. You can get the cookie and redirect information back from the site and then do a GET redirect using header.
Can you not update the action to simply post directly to that form? Otherwise, you might want to look into something like curl: http://ca.php.net/manual/en/function.curl-exec.php
You'll pretty much re-use the header redirect syntax with the parameters but instead you'll tell it to be a post.
redirect to a page on a different server and post parameters to it
thanks to internet standards, that's impossible.
if it's third-party site, let user to interact with it directly. do not interfere between them, it smells
If you want to develop secure applications then you should be aware that http://www.thereceivingpage.com/process.php is vulnerable to Cross-site Request Forgery (CSRF), meaning that anyone, from any site, can post form data to process.php.
process.php should be checking for a token (which www.thereceivingpage.com transmitted to the user as part of the form) and should be rejecting form submissions that don't contain the token to prevent submissions coming from anywhere but www.thereceivingpage.com and thus protecting your users from being manipulated into making requests they didn't want to.
In addition to your concern about the size of the GET requests you cause the client to make when redirecting, it's also not a good practice to turn POST requests into GET requests.
The best solution is to completely rethink the notion of delivering a form from one site to be submitted to a different site.
You can manually set headers and send request or you can use curl
see this
http://www.askapache.com/htaccess/sending-post-form-data-with-php-curl.html

What Differences Are There Between Form Submissions and cURL Requests?

I'm trying to submit data to SalesForce.com, but I'd like to do it through AJAX. Since there are restrictions to deter XSS, I'm having jQuery use AJAX to submit to a PHP page on my server and then having that page simply forward the formdata it's passed along to the proper URL.
If I submit the form with JS turned off, everything goes through fine. If I turn it on, Salesforce confirms receipt of the data (in debug mode), but it's not showing up in my queue, or anywhere really, in SF. SF spits back all of the fields it was passed, and it's spitting back every field that I have in my form, properly filled out.
Are there any differences between submitting something through this method (jQuery's $.ajax() to PHP cURL) and through the native HTML Submit button? Something that could be causing SF to register the data, but register it differently? I've tried adding CURLOPT_HEADER/CURLOPT_HTTPHEADER information
Well, the only thing that's different that you can't fake is the IP address of the request. Depending on how tough the protection is that salesforce is using, you may not be able to spoof from a separate IP address (it would detect and deny the request).
Everything else should be 100% fakeable (headers, etc). What I would suggest is that you get firebug or TamperData and look at the raw headers being sent to salesforce from your browser normally. Then replicate that exact request from PHP. If you need other information, you could detect it in JS and pass it to PHP (Cookie information, browser info, etc)...
$.ajax() transmits cookies from the client browser; and it also adds a "X-Requested-With: XMLHttpRequest" request header.
Maybe try adding the (external) IP address of the machine that is running the php code to the list of trusted networks in salesforce. Login to salesforce, and go to setup -> security controls -> network access, and add the IP there.
I ran into a similar problem and had to add the ip address of the server that was running the java app that connected to sf and this fixed the problem for me.

How can I hide $_SERVER['HTTP_REFERER']

How can I hide $_SERVER['HTTP_REFERER'] when a user browses to another site via a link from my site?
You can't, you have no control over the headers that are sent to another site. Headers are sent from the browser, to the site being navigated. This means you cannot manipulate them in any way (short of a MITM attack).
You could redirect the user to the site via an intermediary proxy, but that proxy will become the new referrer. e.g.
Your Link -> Proxy -> End result
Not only should this generally not be done, but it is not possible, at least in the way you are describing. It is up to the client to decide what to send in the request headers to a different server, not you.
I should also point out that this has nothing to do with PHP. PHP makes this header variable accessible to you via $_SERVER['HTTP_REFERRER'], but the problem you are trying to solve is avoiding the client from sending the referrer URL to the next server.
A few options:
If your site utilizes HTTPS, then it won't be sent.
If you build a redirector script on your site and use the HTTP Refresh header, the browser will typically not send the referrer, and if it did, you would only be sending the URL of your redirector. For example:
http://www.yoursite.com/redir.php?url=http%3A%2F%2Fwww.google.com
<?php
if (isset($_GET['url'])) {
header("Refresh: 0; " . $_GET['url']);
}
?>
Now, you must be careful with this little script. Anyone could then use your site to make a redirect look like it was coming from you. Also, using this method, anyone can inject whatever headers they want to the client. This is just to give you an idea. Finally, using the refresh header for this goes against the grain of the standards and should not be done.
Finally, Google, Facebook, PayPal, etc. all have redirector scripts. They use some sort of encrypted hash on the URL to determine if they generated the redirect or not. If you don't specify that hash and just give the URL, then the user will be prompted before redirecting. Not friendly.
Look, the bottom line is, there isn't really a reason to do what you are doing. If you are trying to hide something in your URL, then you have bigger problems. Security through obscurity is bad, mmkay?
If you're working in a controlled (intranet say) environment you might benefit from fixing browser configs see eg. http://cafe.elharo.com/privacy/privacy-tip-3-block-referer-headers-in-firefox/ but this is far from ideal.

Can you post data from PHP

I need to cause a user's browser to post data using PHP to another site.
Example: You go to start.com/auto-login-hack (via GET)... then PHP sets the right headers etc. and causes the browser to, via POST, go to 3rdparty.com/login.php with login credentials.
I have done this is the past by having an HTML form and an onload script that submits the form to the destination.
I don't know enough about headers and etc. Is this possible? Can anyone link an example? My search skills just turned up how to use $_POST.
Thanks.
Yes, you can submit POST requests from PHP.
One of your choices is to use curl as shown in this SO question.
However, you cannot do redirects.
You cannot redirect to a POST; this is a limitation of HTTP. You'd have to use JavaScript to cause the browser to post a form.

using Live HTTP Headers

On a website, I enter some parameters in a form, click on search and then get a page with a message "retrieving your results". After the search is complete, I get another page with my results displayed.
I am trying to recreate this programatically and I used Live HTTP Headers to get a peek of what is going on behind i.e the url, form variables,etc. However, I'm only getting information of what goes on up to the page which shows "retrieving your results". Live HTTP Header is not giving me information up to the page which contains the final results.
What can I do to get this final bit of information (i.e the url, form variables, etc)
I use Charles HTTP Proxy for all my HTTP troubleshooting needs. It has a ton of options and works with any browser.
"Web Developer" does this:
https://addons.mozilla.org/en-US/firefox/addon/60
#Mark Harrison
I have webdeveloper installed. Initially, I used it to turn off meta-redirects and referrers to get a clearer picture of the http interaction. But when i do this, the website does not work (i.e it is not able to complete the process of retrieving my search results) so i turned it back on.
I'm wondering if anyone has had to capture http information for a site that has a processing page in between the user input page and the results page
That sounds weird? I'm pretty sure that LiveHttpHeaders should show this. Can you double check that you aren't missing something? Otherwise try with Firebug. It has a tab for "network", which shows all requests made.
I'm using Fiddler2, which is a free (as in beer), highly configurable proxy; works with all browsers, allows header inspection/editing/automodification on request/response.
Disclaimer: I'm in no way affiliated with Fiddler, just a (very happy) user.
I for such problems always fire-on an Ethereal or similar network spying tool, to see exactly, what is going on.
The document is creating a browser component called XMLHTTPRequest , on submit event the object method send() is called, during the waiting time for server response an html element is replaced with a "Waiting message" on succesfull response a callback is called with the new html elements and then inserted in the selected html element. (That's called ajax).
If you want to follow that process you can use Firefox Live HTTP Headers Extension , or Wireshark to view full HTTP headers and actions (get/post/).

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