Click-jacking, often referred to as a "UI redress attack," is a type of attack where an attacker lures users into clicking on an invisible or overlaid element on a webpage. This way, the attacker can coerce users into unknowingly performing actions on a different page than they believe they are on. This article focuses on specific methods of protection against click-jacking.

What is Click-jacking?

Click-jacking is an attack that exploits users' unawareness to make them perform unintended actions on a web page. The attacker typically embeds the target page in an iframe, which is then hidden or overlaid with other content. Users are thus led to click on places that actually activate elements on the hidden page.

Methods of Protection Against Click-jacking

1. X-Frame-Options Header

One of the most effective methods of protection is setting the HTTP header X-Frame-Options. This header tells the web browser that the page should not be embedded in frames (iframes) or objects on other domains. There are three main values for X-Frame-Options:

• DENY - The page cannot be embedded in any iframe regardless of origin.
• SAMEORIGIN - The page can only be embedded in an iframe on the same domain.
• ALLOW-FROM uri - The page can only be embedded from a specified source.

2. Content Security Policy (CSP)

Another strong tool against click-jacking is the Content Security Policy, specifically the frame-ancestors directive. This directive allows websites to specify which domains can embed their pages as iframes. By using frame-ancestors, a page can effectively limit the possibility of being exploited through click-jacking. For example:

Content-Security-Policy: frame-ancestors 'self' example.com;

3. JavaScript Defense Scripts

Although not as robust as server solutions, JavaScript scripts can provide an additional level of protection. One approach is to detect if the page is embedded in an iframe and if so, redirect the entire page. Example script:

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

4. User Visual Alerts

Educating users is also important. Alerting users to potential risks of click-jacking and providing information on how to recognize suspicious behavior can significantly reduce the success rate of these attacks.

Protection against click-jacking is key to ensuring user safety on the internet. By implementing the X-Frame-Options header, Content Security Policy, using JavaScript defense scripts, and educating users, web applications can significantly reduce the risk of successful click-jacking attacks.