<?php $id = $_GET['id']; // Gets "1" from the URL $query = "SELECT * FROM products WHERE id = $id"; $result = mysqli_query($connection, $query); $product = mysqli_fetch_assoc($result); ?> <h1><?php echo $product['name']; ?></h1> <p>Price: $<?php echo $product['price']; ?></p> This code works perfectly on a developer's local machine. However, when deployed to the live web, becomes a nightmare for three specific reasons. The 3 Catastrophic Risks of Using "?id=1" 1. SQL Injection (The #1 Killer) Because the code above directly injects the $_GET['id'] into the SQL query, a hacker does not have to send ?id=1 . They can send:
$slug = $_GET['slug']; $stmt = $pdo->prepare("SELECT * FROM products WHERE slug = :slug"); In 2023, a small electronics retailer contacted our security team. Their site followed the classic "php id 1 shopping" pattern. A hacker used a tool called sqlmap on their product.php?id=1 endpoint. php id 1 shopping
ALTER TABLE products ADD COLUMN public_id CHAR(36) NOT NULL UNIQUE; UPDATE products SET public_id = UUID(); Now your URL becomes: product.php?id=3f7e8a9b-2c4d-4e5f-8a9b-0c1d2e3f4a5a SQL Injection (The #1 Killer) Because the code
product.php?slug=red-cotton-t-shirt
Modify your products table:
Imagine the URL: account.php?id=1 (Viewing user #1’s orders) account.php?id=2 (Viewing user #2’s orders) A hacker used a tool called sqlmap on their product