Comment 4 for bug 1239417

I assumed Ubuntu is used as a host machine, my bad. I now reread the original post and saw that Mac OS X is used.

What I mean is that you need VirtualBox 4.3 Guest Additions on the guest Ubuntu 13.10, but official Ubuntu 13.10 box has only VirtualBox 4.2.16.
Since the Guest Additions version must match the host machine VirtualBox version, it means you need VirtualBox 4.3 on your host machine as well.

When you manage to install Guest Additions for version 4.3 on the Ubuntu 13.10 box, you can then save it for later use as described here: http://docs-v1.vagrantup.com/v1/docs/getting-started/packaging.html