What measures can developers take to secure client-side rendering with Bun

Validate and Sanitize User Input

Always validate and sanitize any user input passed to React Server Components before using it in server-side code. Treat all user input as potentially malicious. Validate the input format, length, and characters to prevent injection attacks like SQL injection or XSS. Use a sanitization library like DOMPurify to remove any malicious code from user input.

Implement Proper Authorization

Ensure that the user making the request to a server component has the necessary permissions to perform that action. Check the user's role and permissions against the requested action. Never blindly trust the user ID or other identifiers passed to a server component. Always verify the user is authorized to access or modify the requested data.

Use Parameterized Queries

When interacting with a database from a server component, always use parameterized queries instead of string concatenation. Parameterized queries safely escape user input to prevent SQL injection attacks. Libraries like Prisma and Sequelize provide an easy way to use parameterized queries.

Implement CSRF Protection

React Server Components are still vulnerable to CSRF attacks. Implement CSRF protection by:

- Verifying a CSRF token on server-side requests
- Using SameSite cookies
- Implementing a referrer check

Keep Dependencies Up-to-Date

Keep all dependencies, including Bun and React, up-to-date to ensure you have the latest security patches. Outdated dependencies can introduce vulnerabilities.

Use Environment Variables for Secrets

Never hardcode API keys, database credentials, or other secrets in your code. Always load them from environment variables. Make sure to properly configure your environment variables in production.

Limit Exposure of Server Components

Limit which components are exposed as server components. Only make components that need to run on the server into server components. The more components that run on the server, the larger the attack surface.

Implement Rate Limiting

Implement rate limiting on server components to prevent brute force attacks and enumeration. Limit the number of requests a user can make in a given time period.

Secure WebSocket Connections

If using WebSockets with Bun, ensure the WebSocket connection is secured with TLS. Verify the client's identity and authorize their actions.

By following these security best practices, developers can build secure client-side rendered applications with Bun while still taking advantage of the performance benefits of server components. Proper input validation, authorization, and secure coding practices are key to preventing vulnerabilities.