Input Validation

Add input validation and sanitization throughout the codebase:

1. Identify all user input points:

   • API endpoints
   • Form submissions
   • Query parameters
   • File uploads

2. Add validation:

   • Type checking
   • Format validation (email, phone, etc.)
   • Length constraints
   • Whitelist validation where applicable

3. Add sanitization:

   • HTML/Script tag removal for XSS prevention
   • SQL parameter binding
   • Command injection prevention

4. Use validation libraries appropriate for the language/framework

5. Add error handling for invalid input

Success Criteria

• All user input points identified and protected
• Validation schema created for each input type
• XSS protection implemented on all outputs
• SQL injection protection verified
• Proper error messages for invalid input

Completion Checklist

• Audit all API endpoints for input validation
• Create tests for validation rules
• Add documentation for validation patterns
• Test edge cases and boundary conditions
• Verify error handling doesn't leak sensitive info