Add-cart.php Num Jun 2026

To secure scripts handling cart functionality, developers should follow modern web standards as outlined by security resources like the OWASP Top Ten:

// Check if item exists in cart $result = $db->query("SELECT * FROM cart WHERE user_id=$user_id AND product_id=$product_id"); if($result->num_rows == 0) { $db->query("INSERT INTO cart (user_id, product_id, quantity) VALUES ($user_id, $product_id, $quantity)"); } else { $db->query("UPDATE cart SET quantity = quantity + $quantity WHERE user_id=$user_id AND product_id=$product_id"); } ?>

Even worse: some implementations allow num to be a like 101_2 to denote product variant ID, leading to IDOR (Insecure Direct Object Reference) attacks where an attacker can add another user's private or unpublished product to their cart.

: Ensuring the requested quantity is available.

$_SESSION['cart'][$_GET['num']] += $_GET['qty'];

But he didn't type a single line.

Set up alerts for: