That is not a specific security concern. Security is not one thing. I can tell you of blatant security holes that were never fixed in some financials but I won't nor will I exploit them.
It can be done, better than current systems and financials.
This site alone took 50 devs 3.5 years to deploy. it is not a one person job what I am proposing but you'd be surprised what one person with understanding is capable of comparatively.