The following features of Oracle VM VirtualBox can present security problems:
Enabling 3D graphics using the Guest Additions exposes the
host to additional security risks. See
When teleporting a machine, the data stream through which the machine's memory contents are transferred from one host to another is not encrypted. A third party with access to the network through which the data is transferred could therefore intercept that data. An SSH tunnel could be used to secure the connection between the two hosts. But when considering teleporting a VM over an untrusted network the first question to answer is how both VMs can securely access the same virtual disk image with a reasonable performance.
If the network is not sufficiently trusted, the password should be changed for each teleportation as a third party could detect the unecrypted password hash when it is transferred between the target and source host machines.
When
When using the Oracle VM VirtualBox web service to control an
Oracle VM VirtualBox host remotely, connections to the web
service, over which the API calls are transferred using SOAP
XML, are not encrypted. They use plain HTTP by default. This
is a potential security risk. For details about the web
service, see
The web services are not started by default. See
Traffic sent over a UDP Tunnel network attachment is not encrypted. You can either encrypt it on the host network level, with IPsec, or use encrypted protocols in the guest network, such as SSH. The security properties are similar to bridged Ethernet.
Because of shortcomings in older Windows versions, using Oracle VM VirtualBox on Windows versions older than Vista with Service Pack 1 is not recommended.