About Shocker

Hi everybody, I would like to talk about shocker, since it’s nomore usable:
I didn’t own this machine because I understand that shellshocker was the way to get in, but I didn’t understand how.
I mean, nikto didn’t even told me that the machine was affected, and the scan with dirbuster didn’t find a single file in the cgi-bin dir.
Was I on the right road???
I spoilered details on the machine because it isn’t usable, feel free to delete the post if not permitted.