In PHP, what are the implications of relying on the automatic temporary storage of files in the temp directory for processing?

Relying on the automatic temporary storage of files in the temp directory for processing can lead to security vulnerabilities as these files are accessible to anyone with access to the server. To mitigate this risk, it's recommended to store sensitive files in a secure directory with restricted access permissions.

// Specify a secure directory for storing sensitive files
$secureDirectory = '/path/to/secure/directory/';

// Move uploaded file to secure directory
move_uploaded_file($_FILES['file']['tmp_name'], $secureDirectory . $_FILES['file']['name']);