What are the potential issues with using register_globals=on in PHP and why is it recommended to switch it off?

When register_globals is set to on in PHP, it allows user input to be automatically registered as global variables, which can lead to security vulnerabilities such as variable injection and overwrite attacks. It is recommended to switch it off to prevent these issues and ensure a more secure application.

// Set register_globals to off in php.ini file
// This will prevent user input from being automatically registered as global variables
// This can help prevent security vulnerabilities in your PHP application