What potential security risks are associated with using $_SERVER["REMOTE_ADDR"] to determine the IP address in PHP scripts?

Using $_SERVER["REMOTE_ADDR"] to determine the IP address in PHP scripts can be risky because it relies on user input that can be manipulated. To mitigate this risk, it's recommended to use a more secure method like filtering and validating the IP address before using it in your script.

// Validate and sanitize the user input for IP address
$ip = filter_var($_SERVER["REMOTE_ADDR"], FILTER_VALIDATE_IP);
if($ip){
    // Proceed with using the validated IP address
    echo "Valid IP address: " . $ip;
} else {
    // Handle invalid IP address
    echo "Invalid IP address";
}