Which response header defines whether content can be displayed using frames, primarily to defend against clickjacking attacks?

The response header that defines whether content can be displayed using frames, primarily to defend against clickjacking attacks, is X-Frame-Options. This header is crucial for web security as it explicitly instructs the browser on how to handle the display of a page in frames or iframes. Clickjacking is a technique used by attackers to trick a user into clicking on something different from what the user perceives, potentially leading to unauthorized actions on a site.

When a website includes the X-Frame-Options header with specific directives, it can prevent its content from being embedded in frames on other sites. This is important because if a site can be framed, attackers can create deceptive pages that overlay legitimate content, misleading users into performing unintended actions.

The X-Frame-Options header can have values like "DENY" (preventing the page from being displayed in a frame altogether), "SAMEORIGIN" (allowing the page to be displayed in a frame only on the same origin), and "ALLOW-FROM" (allowing the page to be displayed in a frame from specific origins).

In contrast, the other headers listed focus on different aspects of web security and don't directly address frame embedding to combat clickjacking. Cross