Best Practices
- Keep Only Trusted Domains:
Retain only the essential, trusted domains that must be allowed to load resources or frame your application. - Remove Unnecessary Entries:
Eliminate duplicate URLs, outdated third-party domains, unnecessary trailing paths, and unused values from the CSP configuration. - Use Wildcards for Subdomains:
When multiple subdomains need access, use a wildcard instead of listing each one separately. Example: Use https://*.example.com rather than adding https://sub1.example.com, https://sub2.example.com, and so on. This significantly reduces the overall configuration size. - Avoid Localhost:
Do not include localhost or 127.0.0.1 in production CSP configuration, as they are only valid on the local machine, which weakens the CSP policy and increases maintenance overhead.
