How can PHP developers ensure that their scripts do not inadvertently grant superuser privileges?

PHP developers can ensure that their scripts do not inadvertently grant superuser privileges by carefully managing the permissions and access levels within their code. This can be done by avoiding the use of functions or commands that grant superuser privileges, such as exec(), system(), or shell_exec(). Developers should also validate and sanitize all user input to prevent any potential security vulnerabilities.

// Example of how to avoid inadvertently granting superuser privileges
$user_input = $_POST['user_input'];

// Validate and sanitize user input before executing any commands
$clean_input = filter_var($user_input, FILTER_SANITIZE_STRING);

// Avoid using functions that grant superuser privileges
$result = some_function($clean_input);