Video: Shield Your Next.js App With a Content Security Policy

A Content Security Policy (CSP) is vital for shielding web applications from vulnerabilities like cross-site scripting and data injection. In the context of Next.js, a CSP can be implemented by adding directives in the next config file. This helps in defining which sources of content are allowed, enhancing the security of Next.js applications. To validate the CSP and ensure it follows best practices, tools like csp-evaluator.withgoogle.com and observatory.mozilla.org can be used. Implementing a CSP in a Next.js app can be done through meta tags or headers, but creating a header is the preferred method. A nonce is a critical component in CSP, allowing inline scripts to execute securely. It's recommended to start with a report-only CSP to identify issues before full enforcement. Sample Next.js applications with CSP can be found on GitHub, providing practical examples of implementation. The talk also covers how to dynamically apply directives based on the environment and handle CSP reports for policy violations.

This talk has been presented at React Advanced 2023, check out the latest edition of this React Conference.