Installation is simple and takes a few steps, but involves download and updates which would require some bandwidth.
1. Update Fedora
The first thing to do is to upgrade all packages and make the system uptodate.
$ sudo yum distro-sync
2. Install kernel headers and build tools
VirtualBox guest additions are always compiled so they need necessary build tools and kernel libraries. Install them with the following command.
$ yum -y install kernel-devel kernel-headers dkms gcc gcc-c++
After upgrading and installing kernel headers, reboot the system.
3. Compile virtualbox guest additions
Click on Devices > Insert guest additions CD image on the VirtualBox window menu.
The cd image is now available in fedora at /dev/cdrom or /dev/sr0.
Create a directory at home and mount the cd in it.
$ mkdir vboxcd
$ sudo mount /dev/cdrom ~/vboxcd
password for silver:
mount: /dev/sr0 is write-protected, mounting read-only
32Bit cert VBoxSolarisAdditions.pkg
Read full post here
How to setup Virtualbox guest additions on Fedora 20