How does the usage of register_globals impact the functionality of PHP scripts like pic_upload.php?

When register_globals is enabled in PHP, it can pose security risks by automatically turning global variables into PHP variables. This can lead to vulnerabilities like injection attacks. To mitigate this issue, it is recommended to disable register_globals in the PHP configuration settings.

// Disable register_globals in PHP configuration settings
// This can be done by setting register_globals = Off in php.ini file