Go to page

http://yourdomain/cgi-bin/ubr_upload.pl

You should see some thing like

http://video.bizhat.com/cgi-bin/ubr_upload.pl

If not, you need to check the permission of the file, perl script need 755 permission.

You have proper permission, still it shows 500 error, you need to contact your web host to see why Perl script is not working. If you are on Cpanel server, it should work properly once you have chmod it to 755