What are the best practices for handling user input in PHP to prevent XSS and CSRF vulnerabilities?

To prevent XSS and CSRF vulnerabilities in PHP, it is crucial to sanitize and validate user input before processing it. This can be achieved by using functions like htmlspecialchars() to prevent XSS attacks and implementing CSRF tokens to protect against CSRF attacks. 

// Sanitize user input to prevent XSS attacks
$user_input = htmlspecialchars($_POST['input_field'], ENT_QUOTES);

// Validate CSRF token to prevent CSRF attacks
session_start();
if ($_POST['csrf_token'] === $_SESSION['csrf_token']) {
    // Process the user input
} else {
    // Handle CSRF attack
}

Keywords

htmlspecialchars htmlentities filter_input CSRF token input validation

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