What are the security implications of directly accessing form data in PHP without proper validation and sanitization?

Directly accessing form data in PHP without proper validation and sanitization can lead to security vulnerabilities such as SQL injection, cross-site scripting (XSS), and other forms of attacks. To mitigate these risks, it is crucial to validate and sanitize user input before using it in your application.

// Example of validating and sanitizing form data in PHP
$name = isset($_POST['name']) ? htmlspecialchars(trim($_POST['name'])) : '';
$email = isset($_POST['email']) ? filter_var(trim($_POST['email']), FILTER_SANITIZE_EMAIL) : '';