Virtualbox Needs Extension Pack for USB
To share USB in VirtualBox guests, you need to install the extension pack on the host. On Debian, that’s the virtualbox-ext-pack package. At first I thought I needed guest additions or something like that, but that wasn’t the problem.
$ apt show virtualbox-ext-pack
Package: virtualbox-ext-pack
Version: 6.0.12-1
Status: install ok installed
Priority: optional
Section: contrib/misc
Maintainer: Debian Virtualbox Team
Installed-Size: 130 kB
Pre-Depends: debconf
Depends: virtualbox (>= 6.0.12-dfsg-0~) | virtualbox-6.0, virtualbox (<< 6.0.12-dfsg-z) | virtualbox-6.0, wget, debconf (>= 0.5) | debconf-2.0
Homepage: https://www.virtualbox.org
Download-Size: unknown
APT-Manual-Installed: yes
APT-Sources: /var/lib/dpkg/status
Description: extra capabilities for VirtualBox, downloader.
VirtualBox requires an extension pack to provide support for Remote
Desktop Protocol, USB 2.0, PXE booting for Intel network cards, etc.
This PUEL-licensed extension pack is free for personal use.
.
This package downloads the extension pack from internet during install.
N: There is 1 additional record. Please use the '-a' switch to see it