Input Validation

Input validation is a security and data integrity practice that ensures user-provided data meets expected criteria before processing. It involves checking input for correctness, completeness, and safety to prevent errors, malicious attacks, or system failures. This concept is fundamental in software development to protect applications from vulnerabilities like injection attacks and data corruption.

Also known as: Data Validation, Input Sanitization, Form Validation, User Input Checking, Input Filtering

Why learn Input Validation?

Developers should implement input validation whenever handling user input, such as in web forms, APIs, or file uploads, to enhance security and reliability. It is critical for preventing common threats like SQL injection, cross-site scripting (XSS), and buffer overflows, ensuring data consistency and reducing bugs in production systems.

Learning Resources

• docs: OWASP Input Validation Cheat Sheet
• tutorial: MDN Web Docs: Client-side form validation
• course: Coursera: Secure Coding Practices
• video: YouTube: Input Validation Explained
• book: Book: 'The Web Application Hacker's Handbook'