ASP.NET Core security best practices

Authentication and Authorization

• JWT Bearer Authentication
  Securely authenticates API requests using JSON Web Tokens, enabling stateless and scalable user verification.
• Role-Based Access Control (RBAC)
  Restricts user actions based on assigned roles, ensuring only authorized users access sensitive features.
• Policy-Based Authorization
  Enables fine-grained access control by defining custom policies that go beyond simple roles.
• Multi-Factor Authentication (MFA)
  Adds an extra layer of security by requiring users to provide multiple forms of verification.
• OAuth 2.0 Implementation
  Allows secure delegated access to APIs and resources using industry-standard authorization protocols.

HTTPS and Transport Security

• SSL/TLS Configuration
  Encrypts data in transit to protect against eavesdropping and man-in-the-middle attacks.
• HTTPS Enforcement
  Forces all traffic over secure channels, preventing accidental exposure of sensitive data.
• HTTP Strict Transport Security (HSTS)
  Instructs browsers to always use HTTPS, reducing the risk of protocol downgrade attacks.

Input Validation and Data Protection

• Server-Side Validation
  Ensures all incoming data meets expected formats and constraints, preventing malicious input from reaching your logic.
• Data Annotations
  Simplifies validation by decorating models with attributes that enforce rules automatically.
• Custom Validation Attributes
  Allows creation of tailored validation logic for business-specific requirements.
• NET Core Data Protection API
  Provides cryptographic services for protecting sensitive data such as tokens and cookies.

Attack Prevention

• Cross-Site Request Forgery (CSRF) Protection
  Prevents unauthorized commands from being transmitted as authenticated users.
• Cross-Site Scripting (XSS) Prevention
  Blocks attackers from injecting malicious scripts into web pages viewed by other users.
• SQL Injection Prevention
  Stops attackers from manipulating database queries through untrusted input.
• XML External Entity (XXE) Attack Prevention
  Protects against XML parser vulnerabilities that can expose internal files or services.

Cross-Origin Resource Sharing (CORS)

• CORS Configuration
  Controls which domains can access your APIs, reducing the risk of cross-origin attacks.
• Origin Validation
  Ensures only trusted origins can interact with your backend.
• Credential Handling
  Manages how cookies and authentication headers are shared across origins.

Rate Limiting and Throttling

• API Rate Limiting
  Protects your application from abuse by limiting the number of requests a client can make.
• Request Throttling
  Smooths out traffic spikes to maintain application stability and availability.
• Abuse Prevention
  Detects and blocks excessive or suspicious activity to safeguard resources.

Error Handling and Information Disclosure

• Global Exception Handling
  Catches unhandled errors to prevent sensitive information from leaking to users.
• Custom Error Pages
  Provides user-friendly responses while hiding technical details.
• Information Leakage Prevention
  Ensures internal details are never exposed in error messages or logs.

Logging and Monitoring

• Security Event Logging
  Records authentication attempts, access violations, and other critical events for audit and forensics.
• Audit Trails
  Tracks changes and sensitive operations for compliance and investigation.
• Monitoring and Alerting
  Enables real-time detection and response to suspicious activities.

Configuration and Secrets Management

• Environment-Specific Configuration
  Separates settings for development, testing, and production to avoid accidental exposure.
• Secrets Storage
  Safely stores sensitive information like API keys and connection strings outside of source code.
• Configuration Security
  Protects configuration files and ensures only authorized access.

Dependency Management

• Package Vulnerability Scanning
  Identifies insecure libraries and packages before they reach production.
• Dependency Updates
  Keeps all dependencies current to patch known vulnerabilities.
• Third-Party Library Security
  Evaluates and monitors external libraries for security risks.

Session Management

• Session Security
  Protects session data from hijacking and unauthorized access.
• Cookie Security
  Configures cookies with secure flags and proper scope to prevent theft or misuse.
• Session Timeout
  Automatically ends inactive sessions to reduce the risk of unauthorized access.

API Security

• API Documentation Security
  Protects API docs from exposing sensitive endpoints or information.
• Runtime API Protection
  Monitors and defends APIs against threats during operation.

Next in the Series:
Now that you know the core security best practices, our next post will focus on "JWT Bearer Authentication in ASP.NET Core"—helping you implement robust, modern authentication for your APIs.