Four-year-old comment security bug affects 86 percent of WordPress sites (Ars Technica)

I think that web sites have stopped being "documents" and are in fact client/server applications for a long time now, like since Netscape 2, that ship has sailed and sent postcards from the other shore. The fact that the web is primarily an application delivery platform, with document viewing being a built-in application, was a major goal from the outset in the 1990s and is why vendors like MS were so scared, that most things would move into web apps (like it has done now) and they would be left without any leverage in the market (which they kind of don't have now).