Guest additions 'unable to locate program' Kali Linux 2.0

The question is a bit old, but deserves an answer to the root cause of the error, not a work-around.

The root cause of your issue is in /etc/fstab. If yours looks anything like mine, the mount options for /dev/sr0 are probably user,noauto. The user option automatically implies noexec which strips executable bits off all binary files on the mounted file system.

You simply need to add the exec option to your mount statement in /etc/fstab

from:

/dev/sr0    /media/cdrom0    udf,iso9660    user,noauto         0    0

to:

/dev/sr0    /media/cdrom0    udf,iso9660    user,noauto,exec    0    0

This will allow you to execute binaries from optical media.

Cheers,

Rich

I don't know exactly what the cause is but it seems that perhaps it is a permission issue...(not exactly sure)

You can get around this problem by opening up terminal and calling

sh /media/cdrom/VBoxLinuxAdditions.run

Refernce: https://forums.virtualbox.org/viewtopic.php?f=3&t=58799