CentOS 7 with VirtualBox

To install VirtualBox Guest Additions on a CentOS 7 guest run this as root:

rpm -Uvh http://dl.fedoraproject.org/pub/epel/beta/7/x86_64/epel-release-7-0.2.noarch.rpm;
yum -y install dkms kernel-devel-$(uname -r) kernel-headers-$(uname -r);
wget http://download.virtualbox.org/virtualbox/4.3.14/VBoxGuestAdditions_4.3.14.iso;
mount -o loop VBoxGuestAdditions_4.3.14.iso /media/;
/media/VBoxLinuxAdditions.run;

To install VirtualBox on a CentOS 7 host run these as root:

rpm -Uvh http://dl.fedoraproject.org/pub/epel/beta/7/x86_64/epel-release-7-0.2.noarch.rpm;
yum -y install dkms kernel-devel-$(uname -r) kernel-headers-$(uname -r);
yum -y localinstall http://download.virtualbox.org/virtualbox/4.3.14/VirtualBox-4.3-4.3.14_95030_fedora18-1.x86_64.rpm;

https://www.centos.org/forums/viewtopic.php?f=47&t=47116