Content Security Policy (CSP)
Content Security Policy (CSP) is an added layer of security that helps to detect and mitigate certain types of attacks, including Cross-Site Scripting (XSS) and data injection attacks.
To enable CSP, you need to configure your web server to return the Content-Security-Policy HTTP header.
Specifying your policy
Content-Security-Policy: policy
Example
Content-Security-Policy: default-src 'self'
Content-Security-Policy: default-src 'self' example.com *.example.com
Content-Security-Policy: default-src 'self'; img-src *; media-src example.org example.net; script-src userscripts.example.com
Content-Security-Policy: default-src https://onlinebanking.example.com
Content-Security-Policy: default-src 'self' *.example.com; img-src *