Couple of things ...
I think you mean "Traversal", not "Transversal". It's a directory traversal attack, because you're using relative paths (EG ../../../etc/passwd) to traverse the filesystem while avoiding most of the common checks done by software to see that they're not being abused (EG paths don't begin with a '/' in order to detect if a filename is given). Even when checks are in place to attempt the resolution of pathnames, they're not always sufficient - see, for instance, the Microsoft Unicode double-escape directory traversal attack in IIS.
The other issue is considerably more serious, though: what in the name of sodding bloody buggering hell is the webserver doing with access to a key file that ought to be root-owned and that the server ought to have read into memory before dropping the hell away from superuser privileges and certainly before even thinking about accepting queries over the network?