| Issue | Mitigation | |-------|-------------| | | Cast to int: (int)$_POST['num'] | | Negative quantity | Set default max(1, $num) | | Extremely large num | Apply upper cap (e.g., 999) | | No product ID | Reject request | | CSRF | Use CSRF token in form | | Session fixation | Regenerate session ID after login | | SQL Injection | Use prepared statements for DB cart |
Keeps the customer engaged on the category or product landing page.
Never trust user input. We must ensure that the incoming product ID and the requested quantity ( ) are valid integers. Shopping Cart using PHP and MySQL #php add-cart.php num
next in the handler . . . add the follwing loop and variable. $qty = $_POST['qty']; or $qty = $_REQUEST['qty']; then. for($i =0; $ Stack Overflow
// 4. Update cart session if (!isset($_SESSION['cart'])) $_SESSION['cart'] = []; | Issue | Mitigation | |-------|-------------| | |
Because the num parameter is not parameterized, the attacker can extract the entire database.
: Check if the product is already in the $_SESSION['cart'] . If it exists : Add the new "num" to the existing quantity. If it's new : Initialize it with the provided quantity. Implementation Example Here is a secure implementation using PHP sessions: Shopping Cart using PHP and MySQL #php next in the handler
An attacker sends: add-cart.php?num=1\r\n[ERROR] System compromised\r\n&id=105
This article explores the technical function of this script, the security risks associated with it, and how modern developers handle "add to cart" functionality today. What is add-cart.php?