A Security Headers Scan is a process used to assess the security of a website or web application by examining the HTTP response headers it sends to a client's browser. These headers provide important information about how the website handles security-related issues. Here are some common security headers that are typically checked during a security headers scan:
HTTP Strict Transport Security (HSTS): This header instructs the browser to always use a secure (HTTPS) connection when interacting with the website, preventing certain types of attacks like SSL-stripping.
Content Security Policy (CSP): CSP headers define which sources of content are considered valid and can be executed on a web page. This helps mitigate against cross-site scripting (XSS) attacks.
X-Content-Type-Options: The X-Content-Type-Options header prevents browsers from interpreting files as a different MIME type than declared, reducing the risk of content sniffing attacks.
X-Frame-Options: This header controls whether a web page can be displayed within an iframe. It can help prevent clickjacking attacks.
X-XSS-Protection: This header enables or disables the built-in Cross-Site Scripting (XSS) filter in web browsers.
Referrer-Policy: The Referrer-Policy header defines how much information about the current request's origin should be included in the Referer header when navigating to another page.
Feature-Policy: This header allows you to control which web platform features are allowed or disallowed on a web page.
Cache-Control and Pragma: These headers control caching behavior and can help prevent sensitive data from being stored in the browser cache.
Server Header: While not a security header per se, it's a good practice to limit the information disclosed by the Server header to minimize the risk of attackers targeting known vulnerabilities.
Expect-CT: This header enforces Certificate Transparency and can help detect and prevent malicious SSL/TLS certificates.
Public Key Pinning (HPKP): Although deprecated in modern browsers, this header used to allow websites to specify which public keys should be used to establish an SSL/TLS connection.
A security headers scan involves analyzing a website's response headers to ensure they are correctly configured and provide the necessary security protections. Properly configured security headers can help protect against a range of common web application vulnerabilities and attacks. Tools and services like security scanners or browser extensions can be used to perform these scans and assess a website's security posture.
