What are the potential security vulnerabilities associated with using $_SESSION variables to determine page behavior in PHP?

Using $_SESSION variables to determine page behavior in PHP can introduce security vulnerabilities such as session hijacking or manipulation. To mitigate these risks, it is recommended to validate and sanitize user input before storing it in $_SESSION variables. 

// Validate and sanitize user input before storing it in $_SESSION
if(isset($_POST['user_input'])){
    $safe_input = filter_var($_POST['user_input'], FILTER_SANITIZE_STRING);
    $_SESSION['safe_input'] = $safe_input;
}

Keywords

$_SESSION variables security vulnerabilities page behavior PHP error types

Related Questions