Data Input Validation and Error Handling

This question asks whether your application checks and cleans all data that users enter before processing it, and provides helpful error messages when something's wrong. It's like having a security checkpoint that inspects packages before they enter a building - you need to verify that incoming data is safe and legitimate before your system uses it.

Poor input validation is the root cause of most security vulnerabilities, including SQL injection and cross-site scripting attacks that can expose entire databases. Proper validation prevents breaches, ensures data quality, and provides a professional user experience that enterprise customers expect. Without it, you're one malicious input away from a catastrophic breach.

Many teams only validate data on the front-end (user interface) which hackers easily bypass, or they validate some inputs but miss others. Another mistake is revealing too much system information in error messages, giving attackers clues about your infrastructure.