Yes, indeed this is serious. If there are people here that develop with RoR should upgrade. Yesterday someone post about this http://www.insinuator.net/2013/01/rails-yaml/ (It may not be the right thing to do, but it helped me to understand)
There's a microframework in ruby called Sinatra and the mantainer released a gem https://github.com/rkh/rack-protection Maybe it helps someone :) --
