Hi,
First, can you please roll back the security hotfix. Remove the hf900-00010.jar from the \lib\updates folder or if you took the backup of the previous updates jar files replace with them, and then replace the CFIDE folder to the backed up foder, restart the server and then check if you can access the Admin.
If you have a Dev server, first apply the update on that one as you have already applied the security hotfix 13-03, then you have to follow the section 1 and check it.
Regards,
Priyank