Harden

web/server.rb

   get '/search' do
     redirect '/login' unless signed_in?
     params[:type] = 'threads' unless params[:type]
-    params[:page] = 1 unless params[:page]
+    params[:page] = 1 unless params[:page] && params[:page].match(/\d+/)
     params[:page] = params[:page].to_i
+    params[:q] = String.new unless params[:q]
+    params[:username] = String.new unless params[:username]
 
     results = search(params)
     previous_url, next_url = build_urls(params)