Comprehensive Input Validation Strategies
Develop robust input validation routines, including whitelisting, canonicalization, and strict data type enforcement, to neutralize various input-based attacks.
Why Validate Input?
Input validation is the process of ensuring that data provided by a user or another system conforms to expected formats and constraints.
It's your first and most critical line of defense against many types of attacks, like injection, buffer overflows, and even simple logic errors.
Always assume external input is malicious until proven otherwise!
Whitelisting for Safety
When validating input, the safest approach is whitelisting. This means you define what is explicitly allowed, and reject everything else.
- Whitelisting: "Only these characters/patterns are allowed."
- Blacklisting: "These characters/patterns are forbidden."
Blacklisting is dangerous because attackers often find ways around forbidden patterns. Whitelisting is proactive and far more secure.
All lessons in this course
- Advanced SQLi & NoSQLi Techniques
- Comprehensive Input Validation Strategies
- Content Security Policy (CSP) for Backend
- Preventing Command & LDAP Injection