So these are two commands to mount shared folder in a linux host on a linux guest so that the guest has full permission in the shared folders.
This first command should be executed on the guest VM
sudo mount -t vboxsf SHARE_NAME /MOUNT_POINT/ -o rw,users,umask=0000
This next command enables symlink creation and should be executed on the host.
VBoxManage setextradata VM_NAME VBoxInternal2/SharedFoldersEnableSymlinksCreate/SHARE_NAME 1