As the title may possibly suggest, I'm wondering what's more secure for AJAX requests: POST or GET. I can't work out which is better because they're both hidden from the user due to the URI being sent via. AJAX, not in the URL bar.
Thanks,
James
Neither add any security against either man-in-the-middle attacks or the end user. Both can be intercepted and tampered with using Wireshark, Firebug, or other tools.
If you want security against interception, you can use HTTPS. That does not prevent the user from sending requests manually, though.
It's almost trivially easy to inspect the contents of both post and get values. Your best bet, if you do not want the user to be able to get at that data directly, is to encrypt it, and / or send it over ssl.
There are no security differences between POST and GET used in AJAX. They are not hidden from the user - a simple tool like Fiddler would allow the user to see those requests. the payload in both is in plain text (ie, as your script created it). The only difference is that POST payload is in the body of the request and GET payload is in the query params of the URL.
They are not hidden from the user at all; install FireBug on FireFox and they are able to see the URI. Your choice of using GET and POST depends on the data sent; and if you going by REST standards, depending on the operation.
Treat an AJAX call as you would with information coming from the client through a form and through the address bar : Verify and sanctify.
They can view the page source and see where your target URL is and what parameters are being passed either way.
Related
Im using Spring MVC: Spring security.
There is one GET request which downloads a form. I want to know whether the request was made using an hyperlink or from the address bar.
Is there any attribute in the HttpRequest object that can differentiate between the two?
You could use the Referer header to see if the request is coming from a link in another page. See explanations on Wikipedia and the entry in the HTTP spec. Directly entering the URL in the address bar will not have the header in the request.
Since you ask your question in a security context do note that you cannot count on this check because any request can be faked (i.e. I could use a basic command line app to make your application think I'm requesting from a browser). Also, there are plugins that deactivate this feature in browsers for privacy considerations.
I know how to use ajax for submitting a form and all. What I am concerned about is, what is actually happening in the background when a form is submitted via ajax.
How are the values transferred? Encrypted or not? And what is the
need of specifying submission type, I mean get or post, if the URL is
not showing the form fields?
Edit: Found this on w3schools:
GET requests can be cached
GET requests remain in the browser history
GET requests can be bookmarked
GET requests should never be used when dealing with sensitive data
GET requests have length restrictions
GET requests should be used only to retrieve data
POST requests are never cached
POST requests do not remain in the browser history
POST requests cannot be bookmarked
POST requests have no restrictions on data length
How do these apply to ajax form submission?
Basically, when you Ajax-submit a form, it is doing exact same thing as what would happen when you as a user GET or POST submit a form - except that it is done in an asynchronous thread by the browser - i.e. called XMLHttpRequest.
If you submit form as a GET request, all of the form values are stitched together as parameter strings and appended to the URL (form's ACTION URL) - prefixed by a ?. This means anyone who can intercept that communication can read the submitted form data even if request is sent to a HTTPS URL. The POST method sends form data as a separate block (from the URL) and if URL is HTTPS then form data gets encrypted.
It looks like you are just starting out in the world of web development - welcome to the world of programming. I would recommend reading up on some good web development/programming books (I don't want to promote any particular book here). Amazon may help suggest few good ones under "Web Development" kind of search terms.
Also, I suggest that you read up a little on GET vs. POST by googling for it (I can only include one or two links - google will show you hundreds).
For the clear understanding & behind the scene things please refer the links given below.
http://www.jabet.com/
How does AJAX work?
Actually ajax request is same as the normal requests at the server end.
GET or POST has their own use cases. for example: GET has a limit of data transfer depending on the browsers from 1KB to 10 KB. where POST has no such limits.
For a server both AJAX & normal request both are same. so it depends on server code which method you wish to support.
ajax requests are NOT encrypted.
http://www.w3schools.com/tags/ref_httpmethods.asp
It looks like you want a very detailed answer so you can find it yourself:
Google it and read thoroughly the pages (wikipedia for example)
Read http://www.w3.org/TR/XMLHttpRequest/
Inspect the packets between your browser and the server
I am making one website in which the form is submitted using jQuery ajax. I have taken care of most of the security majors like HTTPS, session cookie, encryption etc.
Hence I have minimised the possibility of outside person sniffing or modify my data transfer.
But there can be a valid registered user who wants to play havoc by using Chrome inspect element. He can for example create a for loop in which is calls my jQuery ajax post call.
Can this be possible? How can I avoid this? I am unable to find a better alternative & resort once again to basic form post instead of ajax.
Thanks.
Anything you present client side can be messed with. A user will always be able to modify your front end code, and do what they want with it. This is why you need server side validation.
If you are worried about a repeating post call, it sounds like you are worried about a DOS attack I guess?
Your server configuration should be set up to detect frequent requests from the same user and deny service to it.
I know all about SQL injections, and peeking into javascript files that a website uses, and also that GET requests contain all of the information in a URL.
Is there any security concern that is special to AJAX and only pertains to using AJAX?
For example, sending post requests via AJAX seems completely safe to me. Barring SQL injections, I can't think of one thing that could go wrong... is this the correct case?
Also, are "requests" of any kind that a user's browser sends or any information it receives available to be viewed by a third party who should not be viewing? And can that happen to AJAX post requests ('post' requests specifically; not 'get')?
It's like any other form of data input: validate your values, check the referrer, authenticate the session, use SSL.
Lets consider next scenario: assume I have a web app, and authentication of users is performed through a modal dialog window (lets say, that when a user clicks login button, ajax request is sent and depending on the callback I either close the window or display an error), and I use only HTTP protocol. Why is it considered to be not secure way to do things?
Also, please make sure that a modal dialog window is taken into account, because this is vital info. There may be some data displayed underneath the dialog window and can be accessible if modality is broken.
The question includes both:
How can you break an app security by
utilizing ajax call?
Is Ajax HTTP less secure than a
regular form HTTP?
Whoever told you - he is wrong. The ajax through post is not less secure than post with regular forms. Just because it is the same thing.
Update 1 according to the last edit:
You cannot
No
Argument: the AJAX request is the same http request as any other (such as request sent by html form). Absolutely the same. So by definition it cannot be less or more secure.
I don't know how to explain more and what to say else: ajax is a http request. the same request as your browser does when you open SO page or when you post the SO question form.
I can rephrase your question to something like "Why A is less secure than A". Answer to it: A is not less secure than A, because A is A :-S
Any sensitive data should be channeled through HTTPS. GET data is sent in the querystring. POST data is sent in the HTTP Request header. Ajax can do both. BOTH are not secure. You need a channel level encryption to really secure it.
HTTP isn't secure for private data because the data is transmitted in plaintext. This can be intercepted anywhere between the client and server (eg. wifi.) Ajax over HTTPS would be much better.
I think the issue is that you are using http. No matter how you look at it it wont be secure. If you use https the ajax request will be just as secure as a html form.
Somy answer would be to use https and you will be all set.
I'm no security expert, but I think it might be more secure sending it over HTTPS. Just googling learns me that it can be done securely though:
http://www.indicthreads.com/1524/secure-ajax-based-user-authentication/
http://msdn.microsoft.com/en-us/magazine/cc793961.aspx (focused on ASP.NET)
etc.
Since browsers use the same network stack for HTTP and HTTPS, be it AJAX or not, there is no difference. All the headers, cookies, authentication, etc work exactly the same.