What Is Clickjacking and How Does It Work?

Sorry, not available in this language yet

English
日本語
简体中文

AI-generated code | Harness the power of AI coding assistants while managing the risks.
API Security Testing | Manage software risks with a holistic API security testing program.
AppSec Program Consolidation | Simplify your application security program.
Application Security Testing | Solutions to address security risks at all stages of the application life cycle.
DevSecOps | Solutions to help shift security left without slowing down your development teams.
Software Supply Chain Security | Solutions to identify and manage software supply chain risks end-to-end.
Manage Enterprise AppSec Risk | Scale your application security program without increasing complexity or adding friction.
Cloud & Container Security | Optimize your applications for secure deployment and operation in the cloud.
Open Source License Compliance | Effective solutions for ensuring open source license compliance.
M&A Due Diligence | Identify software risks that could negatively impact the value of acquired IP.
Quality and Security Standards Compliance | Ensure your software complies with the standards critical to customers and regulators.

Static Analysis (SAST) | Analyzing code for security vulnerabilities without executing it.
Software Composition Analysis (SCA) | Analyzing software components for security and license compliance.
Dynamic Analysis (DAST) | Testing running applications for security vulnerabilities.
Interactive Analysis (IAST) | Real-time security testing during application execution.
Penetration Testing | Simulated cyberattacks to identify vulnerabilities.
Mobile Application Security Testing (MAST) | Ensuring the security of mobile applications.
Application Security Posture Management (ASPM) | Managing and improving application security posture.
Fuzz Testing Solutions | Identifying vulnerabilities by inputting random data to applications.

Automotive | Security solutions for automotive industry applications.
Financial Services | Security solutions tailored for financial services.
IoT & Embedded | Security for Internet of Things and embedded systems.
Medical Devices | Security solutions for medical devices.
Public Sector | Security solutions for government and public sector organizations.

Dev and DevOps Teams | Security tools and practices for development and DevOps teams.
Security Teams | Solutions and support for dedicated security teams.
Legal Teams | Resources and compliance tools for legal teams.

Table of Contents

What is clickjacking?
Are there defenses against clickjacking?
What are X-Frame-Options?
What is the Content Security Policy (CSP)?
What to read next

Definition

Clickjacking is an attack that fools users into thinking they are clicking on one thing when they are actually clicking on another. Its other name, user interface (UI) redressing, better describes what is going on. Users think they are using a web page’s normal UI, but in fact there is a hidden UI in control; in other words, the UI has been redressed. When users click something they think is safe, the hidden UI performs a different action.

The attack is possible thanks to HTML frames (iframes), the ability to display web pages within other web pages through frames. If a web page allows itself to be displayed within a frame, an attacker can cover the original web page with a hidden, transparent layer with its own JavaScript and UI elements. The attacker then tricks users into visiting the malicious page, which looks just like a site users know and trust. There is no indication there is a hidden UI layered over the original site. Users click a link or a button, expecting a particular action from the original site, and the attacker’s script runs instead. But the attacker’s script can also execute the expected action to make it appear nothing has gone wrong.

Clickjacking itself is not the end goal of the attack; it is simply a means of launching some other attack by making users think they are doing something safe. The actual attack can be virtually anything possible via web pages. This ranges from malicious actions, such as installing malware or stealing credentials, to more innocuous things, such as boosting click stats on unrelated sites, boosting ad revenues on sites, gaining likes on Facebook, or increasing views of YouTube videos.

Are there any defenses against clickjacking?

There are no perfect defenses against clickjacking. But there are actions you can take to reduce your risk. On the client side, disabling JavaScript is effective, but since so many sites rely on JavaScript, turning it off renders many sites unusable. There are some commercial products that can provide protection while trying not to affect the real use of iframes. This can work well within an organization, where the products can be rolled out to employee desktops, but it does nothing to protect customers using the organization’s websites.

What are X-Frame-Options?

Another option is to use the X-Frame-Options HTTP header. It allows an application to specify whether frame use is simply denied, via the DENY value, or the use of frames is allowed, by the SAMEORIGIN or ALLOW-FROM values. Mainstream modern browsers do support this header option, but other browsers may not.

Possible X-Frame-Options:

    X-Frame-Options: DENY
    X-Frame-Options: SAMEORIGIN
    X-Frame-Options: ALLOW-FROM https://example.com/

What is Content Security Policy (CSP)?

The final and more modern option for clickjacking defense is to use Content Security Policy (CSP) and its frame-ancestors directive. This directive allows the application developer to disallow all frame use or specify where it is allowed, similar to X-Frame-Options. CSP is not available in all browsers, and browser plugins and add-ons may be able to bypass the policy. If both the X-Frame-Options header and CSP frame-ancestors are used, browsers are supposed to prefer CSP’s directives, but not all will.

Possible CSP frame-ancestor settings:

    Content-Security-Policy: frame-ancestors 'none'
    Content-Security-Policy: frame-ancestors 'self'
    Content-Security-Policy: frame-ancestors example.com

Because none of these defenses are perfect, defense-in-depth is a good practice, and there is nothing wrong with using all three defenses on your websites.