How to reproduce:
1. Extract usbvideo.sys and usbvideo.inf from the Windows Server 2003 SP2 (which can be downloaded here: https://www.microsoft.com/en-us/download/details.aspx?id=41) to %WINDIR%\system32\drivers\ and %WINDIR%\inf\ resp.
2. Right click on usbvideo.inf and "Install".
4. After the next boot connect the webcam (in my case - Logitech Webcam C170) from the VM window menubar: "Devices" -> "Webcams" -> "[your webcam model]".
After the last step the system hangs if the usbvideo driver is installed. If not, after connecting appears the new device installation window and in devmgr webcam recognizes as other device, i.e. without driver, and system doesn't hangs.
In Windows 2003 this driver is present by default and after connecting the webcam it recognizes correctly and works immediately, without installing any third-party driver(s).
I tested it with 0.4.9-dev-350 in VirtualBox 5.1.34.
P.S.: I know that there is no UVC webcam support in ReactOS yet, but I hope that it may work with needed driver from XP or 2003 for now.