What are the potential pitfalls of setting cookies in PHP?

Setting cookies in PHP can lead to potential security vulnerabilities if not done properly. One common pitfall is not sanitizing user input before using it to set a cookie value, which could lead to injection attacks. To mitigate this risk, always sanitize and validate user input before setting it as a cookie value.

// Sanitize and validate user input before setting it as a cookie value
$cookieValue = filter_var($_POST['user_input'], FILTER_SANITIZE_STRING);

// Set the cookie with the sanitized value
setcookie('cookie_name', $cookieValue, time() + 3600, '/');