An exploit for PHP's COM objects on the 5.x series has been reported by shinnai - an issue that allows for a bypass of safe_mode and disable_function settings.
The exploit has been published as a PHP file for easy testing on your Windows/PHP installation (it was tested on WinXP Pro SP2 on both the CLI and Apache). No additional modules are needed for this exploit - only the COM functions and a Windows system.
The issue comes from an overflow in the str_repeat function allowing for the execution of whatever applications the developer wants on the remote Windows machine (including the ability to create and remove files and directories). There is no path for this issue currently (should be corrected in the next minor PHP release).