Security Best Practices

Apply these security principles when developing backend services, microservices, and any code handling sensitive data or external inputs.

Input Validation and Sanitization

• •Apply input validation and sanitization rigorously, especially on inputs from external sources
• •Validate all user inputs at the boundary of your application
• •Use allowlists over denylists when validating input
• •Sanitize data before storing or displaying to prevent injection attacks
• •Implement strict type checking and schema validation

Authentication and Authorization

• •Use secure defaults for JWT, cookies, and configuration settings
• •Implement proper token expiration and refresh mechanisms
• •Store secrets securely using environment variables or secret management services
• •Never hardcode credentials or API keys in source code
• •Use secure password hashing algorithms (bcrypt, Argon2)

Permission Boundaries

• •Isolate sensitive operations with clear permission boundaries
• •Apply the principle of least privilege throughout the system
• •Implement role-based access control (RBAC) where appropriate
• •Audit and log access to sensitive resources
• •Use separate service accounts for different components

Resilience and Protection

• •Implement retries, exponential backoff, and timeouts on all external calls
• •Deploy circuit breakers and rate limiting for service protection
• •Consider distributed rate-limiting to prevent abuse across services (e.g., using Redis)
• •Implement request throttling to prevent denial of service
• •Use connection pooling with appropriate limits

Secure Configuration

• •Use HTTPS/TLS for all network communications
• •Configure secure HTTP headers (HSTS, CSP, X-Frame-Options)
• •Disable verbose error messages in production
• •Keep dependencies updated and scan for vulnerabilities
• •Use secure defaults and fail securely

Error Handling

• •Implement comprehensive error handling throughout the application
• •Never expose stack traces or internal details to end users
• •Log security-relevant events with appropriate detail
• •Propagate context appropriately for debugging while maintaining security
• •Handle authentication and authorization failures gracefully

Secrets Management

• •Use environment variables or dedicated secrets managers
• •Rotate credentials and keys regularly
• •Implement proper key management practices
• •Avoid logging sensitive information
• •Use encryption at rest for sensitive data storage

SQL Injection Prevention

• •Use parameterized queries or prepared statements
• •Never concatenate user input into SQL queries
• •Use ORM features that automatically escape values
• •Validate and sanitize all database inputs
• •Limit database user permissions

Cross-Site Scripting (XSS) Prevention

• •Escape all output rendered in HTML
• •Use Content Security Policy headers
• •Sanitize user-generated content before display
• •Use framework-provided escaping functions
• •Avoid innerHTML and similar dangerous APIs

Cross-Site Request Forgery (CSRF) Prevention

• •Implement CSRF tokens for state-changing operations
• •Verify origin and referer headers
• •Use SameSite cookie attribute
• •Require re-authentication for sensitive actions
• •Implement proper session management

API Security

• •Implement API authentication (JWT, API keys, OAuth)
• •Use rate limiting to prevent abuse
• •Validate request content types
• •Implement request size limits
• •Log API access for auditing

Dependency Security

• •Regularly audit dependencies for vulnerabilities
• •Use lockfiles to ensure consistent versions
• •Remove unused dependencies
• •Monitor security advisories for your stack
• •Implement automated vulnerability scanning in CI/CD