VirtualBox Guest Additions add Shared Folders, a shared clipboard, and drag-and-drop. Shared Folders mounts host directories into the guest, a direct host file read and write primitive, and the clipboard and drag-and-drop channels move data across the boundary. These are conveniences commonly left on in lab and analysis VMs.
# Inside a Linux guest with Guest Additions and a shared folder
mount | grep vboxsf
ls /media/sf_<share>/ # host directory exposed to the guest
# Writing here reaches the host filesystem
Exploitation notes#
- Shared Folders turns a guest foothold into host file access with no exploit; writing into a shared path can plant a payload on the host.
- The shared clipboard leaks data in both directions and has been an information-disclosure and parsing-bug surface.
- These features require Guest Additions and explicit configuration, so their presence is the precondition to check.