Trusting Client Data: Server-Side Validation Guide
Why you can never trust data from the client, how attackers manipulate requests, and what server-side validation must always cover.
Published:
Tags: security, validation, mistakes
Never Trust Client Data: Input Validation and Server-Side Checks The client sends whatever it wants. This is not a design flaw — it is the nature of HTTP. Any user with basic technical skills can modify request parameters, bypass JavaScript validation, intercept network traffic, and send arbitrary data to your server. The application security principle "never trust client data" is not a suggestion; it is the foundation of every other security control. What Happens When You Trust the Client Price Manipulation An e-commerce site calculates the total price client-side and sends it with the order: If the server uses the from the request body to charge the customer, an attacker buys a $2,000 laptop for a penny. Role Escalation An application sends the user's role in the request, trusting the…
All articles · theproductguy.in