What are best practices for securing .NET Core applications in IIS to prevent 403 Forbidden errors?

Best practices include minimizing the number of resources that require authentication, implementing role-based authorization, regularly reviewing and updating permissions, using strong authentication methods (e.g., multi-factor authentication), validating user input to prevent exploits, and keeping the application and IIS updated with the latest security patches. Consider using a centralized identity management system (e.g., Azure Active Directory) for authentication and authorization to simplify management and improve security.