Checks

Cross-Origin-Resource-Policy (CORP) is present

The response includes Cross-Origin-Resource-Policy.

Why it matters

CORP tells browsers which other origins may load this response as a subresource.

What to do

same-origin or same-site is the usual choice for documents that should not be embedded elsewhere.

Reference

Security response headers reduce XSS, clickjacking, and protocol downgrade risk.

OWASP Secure Headers Project