That’s a nice attack surface, it’d be a shame if someone hacked it… What appears to be straightforward functionality – upload a document, edit together, save changes – actually requires defending against sophisticated attacks across multiple vectors simultaneously. Every document becomes a potential weapon. Every user session creates new vulnerability...

At Collabora Online we say don’t redevelop the wheel, integrate it! The temptation is real, modern browser technologies offer such a rich baseline of functionality why wouldn’t you consider developing your own editor? Rich text editors are abundant, collaborative frameworks exist and the fundamental problems of saving, formatting and typing...