In my case (VM ubuntu 14.04 on an WIN7 system), I open /var/log/kern.log, and search for CD-ROM, I find that in ubuntu 14.04, VBOX CD-ROM is recognized as SCSI CD-ROM, and attached to /dev/sr0 kernel:[ 1.456xxx] scsi 1:0:0:0: CD-ROM VBOX CD-ROM 1.0 PQ: 0 ANSI: 5

kernel:[ 1.460xxx] sr 1:0:0:0: Attached scsi CD-ROM sr0

Now, after click the menu ‘Device’ -> ‘Install Guest Additions’, then type the following command: sudo mount /dev/sr0 /media/cdrom

and the ISO file is mounted on /media/cdrom

so, after this run: cd /media/cdrom sudo ./

windowsĿ¼ mount -t cifs // /home/mnt -o username=baihe,password=fond