What are the limitations of directly extracting variables from HTML forms in PHP?

Directly extracting variables from HTML forms in PHP using methods like $_POST or $_GET can pose security risks such as SQL injection and cross-site scripting attacks. To mitigate these risks, it is recommended to sanitize and validate user input before processing it in your PHP code. This can be done using functions like filter_input() and htmlentities() to ensure that the data is safe to use. 

// Sanitize and validate user input from a form
$name = filter_input(INPUT_POST, 'name', FILTER_SANITIZE_STRING);
$email = filter_input(INPUT_POST, 'email', FILTER_VALIDATE_EMAIL);

// Process the sanitized input
if($name && $email) {
    // Perform actions with the sanitized data
} else {
    // Handle invalid input
}

Keywords

HTML forms PHP security vulnerabilities data validation injection attacks

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