If the script directly injects the num variable into a SQL query without validation, an attacker can manipulate the query.
$stmt = $pdo->prepare($sql);
The hum of the lights shifted. The room didn't go dark; it just started to... unprint.
By sending a single request with an absurdly high num value, or by sending thousands of sequential requests via a simple script, an attacker can flood the cart session. add-cart.php num
"Infinite stock," Elias whispered, his fingers flying across the mechanical keyboard. If someone could "add" negative items, they weren't buying; they were injecting inventory into the system—or worse, triggering a refund for an item they never owned.
Use code with caution. Security Vulnerabilities and Mitigation
Ensure num is always an integer. Use (int)$_GET['num'] in PHP to force the type. If the script directly injects the num variable
Because the cart is tied to the session ID (usually stored in a cookie), an attacker can force a victim to use a known session ID. If add-cart.php doesn’t regenerate session IDs after login, the attacker can view the cart.php page later and see exactly what the victim added.
To support this frontend functionality, the PHP script must be modified to return a JSON response instead of a header redirection:
For persistent carts that remain across different devices or sessions, add-cart.php unprint
In many early PHP shopping carts, add-cart.php served as the processing script for adding items to a user's session-based shopping basket. The parameter num (short for number) usually represents the or SKU being added.
Using simple query parameters like add-cart.php?num= without rigorous backend validation opens up several technical and security issues. 1. Insecure Direct Object References (IDOR)