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Preventing Web Application Attacks (Input Validation)

Cyber Security Mastery: From Zero to Hero

Secure Coding Principles

Web application defense relies heavily on enforcing strict controls on all user input.

Input Validation, Sanitization, and Escaping

  1. Validation: Ensure the input matches the expected type, length, and format (e.g., a user ID should only contain digits, not symbols or script tags).
  2. Sanitization: Removing dangerous characters or code structures from the input (e.g., stripping <script> tags).
  3. Output Encoding/Escaping: Converting output data into a safe format before displaying it to the user. For example, converting < to &lt; so the browser displays the tag as text instead of executing it as HTML (essential for XSS defense).

Web Application Firewalls (WAF)

A WAF is an application-layer firewall designed specifically to protect web applications by inspecting HTTP traffic for common attack patterns (like SQLi payloads or XSS vectors) and blocking them before they reach the web server.