Description

This publicly exposed API endpoint was found responding with HTML or browser-rendered content and does not implement the Content Security Policy (CSP) header. Since the response content of this API can be rendered by a browser, this header specifies which domains the browser should consider as valid sources and prevent unwanted executable scripts, and other resources.

Remediation

Implement the Content Security Policy (CSP) header in all API responses that return browser-rendered content.

Examples when this header is useful:

# Swagger UI docs
Content-Security-Policy: default-src 'self'; script-src 'self' 'unsafe-inline' https://cdn.jsdelivr.net; style-src 'self' 'unsafe-inline' https://cdn.jsdelivr.net; img-src 'self' data:; connect-src 'self' https://api.example.com