How do I test if my website prevented Clickjacking? - php

I was asked to check how to prevent Clickjacking on our website.
I did some research and this is what I understand, please correct me if I'm wrong:
The attacker will use iframe to layer their website over your website, then make their iframe transparent.
When user click on a button on our website, they are actually clicking on hacker website.
To prevent this, disable iframe on our website.
I went to this website to check, but I got this error:
Couldn’t find the X-Frame-Options header
in the response headers.
What it means? I'm not sure.
I also searched online and found that you need to add this code in .htaccess
<IfModule mod_headers.c>
Header always append X-Frame-Options SAMEORIGIN
</IfModule>
But how do I know if it works?

Clickjacking is about an attacker using an iframe on their website to include yours, with tricks like making your website's iframe transparent. The point is that if a user is logged on to your website (the victim), your website will load the user's content, and the attacker can visually position elements on their website (over your invisible website's iframe for example) so that an unsuspecting user visiting the attacker website will click things in your application. This works, because without further protection of the authentication token (eg. session cookie), your website will just load the user's authenticated content in the iframe.
You could argue that if it loads in the iframe on the attacker's site, why don't they just read or do whatever they want. That's not possible though, because the same origin policy prevents javascript on the attacker's origin from accessing content from another origin (yours), even if it's on the same page in an iframe. But they can possibly make the user perform actions by inadvertently clicking stuff they didn't want to.
This was used to gather likes on Facebook for example, Facebook was loaded in an invisible iframe on malicious sites, and then something like an advertisement's close button was positioned right over a Facebook like button - you tried to close the annoying ad, and in fact liked something you didn't want to.
One protection against this is that your app (or Facebook in the example above) should not allow itself being displayed in an iframe. And that's exactly what X-Frame-Options does. With the value 'deny' it will just never be displayed in an iframe, with 'sameorigin' your own origin (~domain name) can display parts of itself in iframes, but other origins cannot (so an attacker cannot include your site on a different domain).
X-Frame-Options is an http response header, so to check that it works, you can use the network tab of the developer tools in your browser. In most browsers you hit F12, choose the network tab, load your website, find and click the initial request that downloaded the actual page, and you can inspect the list of response headers. That should include X-Frame-Options with the value 'deny' or 'sameorigin'.
You can also use online tools to perform these simple scans (see the other answer for an example), but I think it's worth to actually understand what and why you're doing.

You can get the more details of X-Frame-Options on below https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Frame-Options
You can add below snippet code on last of your server .htaccess file and test the site on https://clickjacker.io/test.
<IfModule mod_rewrite.c>
Header always set X-Frame-Options "SAMEORIGIN"
</IfModule>

Related

Detect if my page is a clickjacking destination

Is there any option to detect if my page is being loaded from a clickjacking page?
I mean, does not matter if the page is the origing of the clickjacking(I've setted the X-FRAME-OPTIONS header), the thing is if from a clickjacked page users are browsing to mine page.
The first solution I found is to control the HTTP-REFERER, but is a hard work because I can't control all my traffic.
Sorry for my english.
Unless you intend for external sites to be able to POST to yours, if you have a POST request originating from another server, it's probably click jacking:
if($_SERVER['REQUEST_METHOD'] == 'POST' && !strstr($_SERVER['HTTP_REFERER'], 'mydomain.com') {
//probably clickjacking
}
If you have pages that use GET that are susceptible to clickjacking, you can either add a check for the HTTP_REFERER on a per-page basis, or change the page to use POST (which is usually best for something which does an update).
One of your options is to set your website header: "X-Frames-Options" to "SAMEORIGIN"
This should prevent your website from being loaded into iframes and frames unless the originating page is in your domain.
Note that this will only work for certain browsers, for example I don't think this will work with IE7 and below and I don't think it works with chrome. This will at least reduce your attack surface a little bit.
Apache:
Header always append X-Frame-Options SAMEORIGIN
MDN - The X-Frame-Options response header
EDIT: Now that I understand better...
Perhaps you can use code similar to this:
if (window.top !== window.self) {
// do something here
}
This is one way to detect if the page is loaded into an iframe. You could set a cookie here, call a WebService here, or use window.location.href to navigate.
Here is an example of the "frame-busting" defense for click jacking:
Clickjacking Defense
-KB

Redirect, but hide referrer

Lets say I have a URL, www.mysite.com/go that I want to redirect to www.anothersite.com/site.php?id=999
The trick is, I do not want anothersite.com to be able to see that the request came from mysite.com. It should look like the address www.anothersite.com/site.php?id=999 was typed into the addressbar manually by the user.
It is important to note, that this has nothing to do with Google Analytics, and there will never exist an anchor link to www.mysite.com/go anywhere. Instead, the user will manually input www.mysite.com/go in the address bar (which is easier to remembar than the long URL).
How is this achieved? The technology in question is PHP. I imagine that it can be achieved with the header() function, but google searches reveal that this only works with https, not http. Can I via PHP control what the client provides of referrel information when the redirect is performed? I guess that if I want it to look like the address was typed into the address bar, I would have to blank out the referrer information. Is it possible?
It's not possible by means of a HTTP Redirect. You don't have any control over the outgoing referrer header as the browser handles it entirely client-side.
Your only real option that you can directly control is to use HTTPS. Referrers with a value of a HTTPS page are not carried forward by browsers.
Example flow:
http://www.mysite.com/go (so any existing links don't have to change)
https://www.mysite.com/go
http://www.anothersite.com/site.php?id=999

Link without referer

How can I make it so when the site visitor of mysite.com clicks a link, like http://google.com, the referrer page is not sent to the target website ?
Is this possible with PHP ?
Basically I want the linked site to not be aware where the visitor came from
I don't think it is possible, as the HTTP referrer information is sent by the browser. You can install browser plugins to prevent sending referrers, but not directly with PHP.
Update: I just found this
If a website is accessed from a HTTP Secure (HTTPS) connection and a link points to anywhere except another secure location, then the referrer field is not sent.
The upcoming standard HTML5 will support the attribute/value rel = "noreferrer" in order to instruct the user agent not to send a referrer.
Source: http://en.wikipedia.org/wiki/HTTP_referrer#Referrer_hiding
The referer is set by the browser, not the server, so broadly speaking, you can't really control this.
You may be able to find ways to mask mysite.com by redirecting the user through an intermediary site to google.com. I wouldn't recommend this, though.
No. Not possible. The client (broswer) is responsible for that HTTP header. A browser might even choose to not (ever) send it. (I'm not sure about the exact protocols/specifications of when to send it.)
edit
There might be a trick. (But I don't know it.) Maybe some JavaScript or header cancelling image or something nasty.

HTTP Referer not always being passed

I have an application which records users visits. None of these visits are directly accessed, 100% of these visits are referred from another site.
I am passing $_SERVER['HTTP_REFERER'] through to the database. Approximately 35% of the logged entrees pass a referer, the rest are blank.
Is there a reason for this?
There are a couple of number of reasons why HTTP_REFERER might be blank.
You have to understand it's an environment variable given by the browser. Meaning users can remove it or even change it, if they so intend to.
Users accessing the link from a bookmark, history or by typing the link manually do not have a referer.
IE has also been known to remove the referer in situations revolving around javascript. Such as window.open, window.location and even setting target="_blank" in anchors or meta refresh.
Clicking an embedded link in a chat application, PDF/Word/Excel document, will also not set a referer.
Using AJAX, file_get_contents, fopen and other similar functions in other languages will probably not set a referer request.
cURL, fsockopen, applications that have browser-like components might not set a referer.
There are probably more situations when this could happen, I'll update if I can think of anything that seems reasonable.
If a user visits your site directly, there is no referrer. It's also possible they have set it up so their browser never sends the referrer.
According to this answer, browsers do not necessarily send a referrer when doing a meta refresh.
Browsers sometimes will include the referer in the request. But it is not mandatory to do so (the referer is 100% voluntary). Indeed there are various privacy and security issues surrounding the referer (for example, if an HTTPS site refers you to an HTTP site, the browser should not include the referring site as the referer). So don't rely on it.
When linking from one document to another in Internet Explorer 4.0 and later, the Referer header will not be sent when the link is from an HTTPS page to a non-HTTPS page. The Referer header also will not be sent when the link is from a non-HTTP(S) protocol, such as file://, to another page. for more info go to this link
Direct access to your page (typing URL in address bar or from bookmarks, history, etc)
Browser settings (disabled referrer or empty)
if someone requests page content with file_get_contents() function...
It is common when you are stuck finding why it is missing:
- Sometime your referer is https and you are on http, it will be lost.
Otherwise:
- User accessing by inputing url directly.
- A user has bookmarked and come from bookmarks.
- Sometime user keep the url default for browser (similar like bookmark)
- Proxy surfying may remove referer.
- accessing website as bots (search engine)
It also depends on the Transport layer, I encountered an issue where my Consumer Application A was running on the HTTP layer while the Application from where I was sending the request was running on the HTTPS layer.

iframe widget: know which domains are iframing the canvas?

If i have a php generated widget canvas and site's using the widget iframe it with $_GET parameters,
is there anyway to get the domain that's making the request to my canvas page (javascript/php?)?
ie - stop people using my widget that don't have permission...
You can't reliably protect your content without coming up with a password-based system (or something else like that, involving the client presenting some secure credentials). The "REFERER" header is unreliable, but fairly useful if you're not trying to use it for security purposes.
"Referer" shows up as a request header, with that odd spelling. It provides the URL of the page from which the GET request was generated. It's not secure because it's completely under control of the client browser. It may be missing, or it may contain bogus data.

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