Identification of Frame Injection

Frame injection, also known as Clickjacking, is a type of attack where an attacker embeds a maliciously crafted webpage or script into another webpage, typically using iframes, to trick users into performing unintended actions. These actions may include clicking on buttons, submitting forms, or even revealing sensitive information. As a penetration tester, identifying frame injection vulnerabilities involves examining the application's behavior and identifying areas where user interactions might be manipulated. Here's how you can identify frame injection vulnerabilities:


  1. Inspecting Page Source: Examine the HTML source code of webpages to look for iframes or other elements that could be used to embed external content.
  2. Checking for Overlapping Elements: Look for transparent or hidden elements that could be overlaid on top of legitimate content, making it appear as though users are interacting with the underlying page when they are actually interacting with the injected content.
  3. Testing with Automated Tools: Utilize automated tools and browser extensions designed to detect frame injection vulnerabilities. These tools can help identify iframes or suspicious elements that may be vulnerable to manipulation.
  4. Manual Testing: Manually interact with different elements on the webpage to see if unexpected actions occur. For example, try clicking on buttons or links to check if they trigger unintended behavior.
  5. Reviewing HTTP Headers: Analyze the application's HTTP response headers to see if they include X-Frame-Options or Content-Security-Policy headers with appropriate directives to prevent framing.
  6. Browser Developer Tools: Use browser developer tools to inspect the DOM (Document Object Model) and CSS styles of the webpage, looking for any elements that could be used for frame injection.


  • Example 1: During testing, a penetration tester notices that the application allows external websites to embed it within an iframe without proper protections. This could lead to clickjacking attacks where users unknowingly interact with the embedded content.
  • Example 2: The tester discovers that the application's pages contain transparent overlays positioned on top of clickable elements. This could indicate an attempt to disguise malicious actions by overlaying them on top of legitimate content.


  1. Implement X-Frame-Options Header: Set the X-Frame-Options header with the value "DENY" or "SAMEORIGIN" to prevent the page from being embedded in iframes from other domains.
  2. Use Content-Security-Policy: Implement Content-Security-Policy headers with directives like frame-ancestors to restrict which domains are allowed to frame the page.
  3. Clickjacking Protection: Implement frame-busting JavaScript code to prevent the page from being framed by other websites.
  4. Security Awareness: Educate developers about the risks of frame injection and the importance of implementing proper protections in web applications.
  5. Regular Testing: Continuously test web applications for frame injection vulnerabilities, especially after making changes to the application or introducing new features.

By identifying and addressing frame injection vulnerabilities, penetration testers can help organizations protect their users from malicious attacks and maintain the security of their web applications.