Add-cart.php Num May 2026

Let’s walk through a real-world penetration test scenario.

Target: https://vintage-books.com/add-cart.php?num=12

Step 1 – Fuzzing: The attacker uses Burp Suite to fuzz the num parameter with a payload list: 1, 1.1, -1, 999999, 1 UNION SELECT 1, 1%00.

Step 2 – Discovery: A request to add-cart.php?num=1.1 returns a MySQL error: "Unknown column '1.1' in 'where clause'" — SQL injection confirmed.

Step 3 – Exploitation: The attacker crafts add-cart.php?num=12 AND 1=2 UNION SELECT database()-- -. The cart page inadvertently displays the database name (e.g., "vintage_store_db") because the product name lookup fails and falls back to the error message.

Step 4 – Escalation: Within minutes, the attacker has extracted table names, dumped admin credentials, and is now logged into the admin panel. All from a single num parameter.

session_start();
if ($_SERVER['REQUEST_METHOD'] !== 'POST') 
    http_response_code(405);
    die('POST required');
// CSRF check
if (!hash_equals($_SESSION['csrf_token'], $_POST['csrf_token'] ?? '')) 
die('Invalid request');
 add-cart.php num
$productId = filter_input(INPUT_POST, 'product_id', FILTER_VALIDATE_INT);
$quantity  = filter_input(INPUT_POST, 'quantity', FILTER_VALIDATE_INT);
if (!$productId || !$quantity || $quantity < 1 || $quantity > 99) 
die('Invalid product or quantity');

// Fetch product from DB and check stock
// ...
$_SESSION['cart'][$productId] = ($_SESSION['cart'][$productId] ?? 0) + $quantity;
header('Location: cart.php');
exit;

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The phrase "add-cart.php num" typically refers to a specific PHP script and parameter used in older or custom e-commerce shopping carts. A review of this implementation reveals significant security concerns, particularly if it is part of a legacy system. Key Technical Concerns

Predictable Filepath: The file add-cart.php is often listed in security "fuzzing" databases (like FuzzDB and SecLists), meaning it is a common target for automated vulnerability scanners.

Parameter Exposure: The num parameter is frequently used to designate the quantity or product ID. If not properly sanitized, it can be exploited via:

SQL Injection: Attackers may append malicious SQL code to the num value to extract database information.

Price/Quantity Manipulation: Insecure scripts may allow users to input negative values (e.g., num=-1) to reduce the total cart price or manipulate inventory. Common Vulnerabilities

E-commerce scripts with similar structures often suffer from these OWASP-recognized flaws: Let’s walk through a real-world penetration test scenario

Improper Input Validation: Failing to use functions like is_numeric() to verify that the num parameter is a positive integer.

Insecure Direct Object Reference (IDOR): Allowing users to access or edit cart items belonging to other sessions.

Lack of Server-Side Verification: Relying on client-side values for final price calculations rather than re-verifying against the database on the server. Recommended Best Practices

If you are developing or maintaining this script, ensure the following modern PHP standards are met: raft-medium-files.txt - GitHub

... shopping-lists.aspx dumpuser.aspx email-a-friend.aspx rssfeed.aspx store_closed.html contact.htm view.aspx template.html list.

Discovery/Web-Content/raft-medium-files-lowercase.txt - GitLab Primary navigation * seclists. * Iterations. * Repository. about.gitlab.com Shop Product Php Id Shopping Php Id A And 1 1 // Fetch product from DB and check stock //

To secure an add-cart.php script, developers must move all validation logic to the Server-Side.

Never accept price information from the client. The add-cart.php script should only receive the item_id and the quantity. The script should then query the database to retrieve the actual price of the item.

$item_id = intval($_GET['item_id']);
$quantity = intval($_GET['num']);
// Fetch price from DB
$stmt = $pdo->prepare("SELECT price FROM products WHERE id = ?");
$stmt->execute([$item_id]);
$product = $stmt->fetch();
if ($product && $quantity > 0) 
    $unit_price = $product['price'];
    // Add to cart logic using the trusted database price