What methods can I use in JavaScript to detect and prevent clickjacking attacks

Question

I’m looking to secure a web application against clickjacking attacks, where an attacker might try to overlay an invisible iframe to trick users into clicking hidden elements. I’m aware that JavaScript has certain detection capabilities, and I'd like to know what techniques can be used directly in JavaScript to detect and prevent these attacks. Are there reliable ways to prevent framing altogether or detect when a page is being framed?

Any advice on specific methods, such as setting headers or JavaScript checks, would be helpful.

Answer 1

In order to protect our application against clickjacking attacks in JavaScript, we can combine JavaScript detection techniques with HTTP security headers for a strong defense.

1. JavaScript Frame-Busting Code

We can use JavaScript to check if our app is being loaded within an iframe and prevent it if necessary:

if (window.top !== window.self) {
    window.top.location = window.self.location;
}

Now this piece of code will check if the current window is not the topmost window. If it detects framing, it forces the top window to navigate to the current URL, effectively "busting" the frame.

2. X-Frame-Options HTTP Header

We can set this HTTP header to prevent our pages from being embedded in iframes on other domains:

• DENY: Completely blocks the page from being framed.

X-Frame-Options: DENY

• SAMEORIGIN: Allows framing only if it's from the same origin as the page.

We can set these header at the server-side to ensure our page can't be iframed in incompatible browsers.

3. Content Security Policy (CSP) Frame-Ancestors Directive

We can use the CSP frame-ancestors directive to define which domains are allowed to embed our content:

Content-Security-Policy: frame-ancestors 'self'

Over here, the frame-ancestors 'self' setting only allows our own domain to frame the page, adding a layer of protection on compatible browsers.

4. JS-Based Visual Checks

You can also consider implementing visual checks to ensure users are aware of the framing if it's necessary for specific scenarios.

• Either we can detect overlays by monitoring changes in window dimensions.
• Or we can use CSS to display a border or visual cue around the content if it's embedded.

5. Preventing Framing in Legacy Browsers

There are some older browsers which might not support CSP or X-Frame-Options, so we can consider frame-busting scripts as a fallback. We can include these on every page for broader coverage.