Fixes Vagrant network has broken after MacOS upgrade to Big Sur

You will get the error when executing vagrant up:

➜ vagrant up
Bringing machine 'default' up with 'virtualbox' provider...
==> default: Checking if box 'bento/ubuntu-18.04' version '202008.16.0' is up to date...
==> default: Clearing any previously set network interfaces...
There was an error while executing `VBoxManage`, a CLI used by Vagrant
for controlling VirtualBox. The command and stderr is shown below.
Command: ["hostonlyif", "create"]
Stderr: 0%...
Progress state: NS_ERROR_FAILURE
VBoxManage: error: Failed to create the host-only adapter
VBoxManage: error: VBoxNetAdpCtl: Error while adding new interface: failed to open /dev/vboxnetctl: No such file or directory
VBoxManage: error: Details: code NS_ERROR_FAILURE (0x80004005), component HostNetworkInterfaceWrap, interface IHostNetworkInterface
VBoxManage: error: Context: "RTEXITCODE handleCreate(HandlerArg *)" at line 95 of file VBoxManageHostonly.cpp

How to fix it:

1. Allow access to Oracle Inc:

Go to System Preferences > Security & Privacy Then hit the “Allow” button to let Oracle (VirtualBox) load.

2. Restart VBox

sudo /Library/Application\ Support/VirtualBox/LaunchDaemons/VirtualBoxStartup.sh restart

Now try vagrant up again