class UsersController < ActionController::Base CONSTANT = "constant" CONSTANT_WITH_FREEZE = "constant-with-freeze".freeze def create file = params[:file] open(file) # BAD IO.read(file) # BAD IO.write(file) # BAD IO.binread(file) # BAD IO.binwrite(file) # BAD IO.foreach(file) # BAD IO.readlines(file) # BAD URI.open(file) # BAD File.open(file).read # GOOD Kernel.open(file) # BAD File.open(file, "r") # GOOD Kernel.open("constant") # GOOD IO.read("constant") # GOOD Kernel.open("this is #{fine}") # GOOD Kernel.open("#{this_is} bad") # BAD open("| #{this_is_an_explicit_command} foo bar") # GOOD IO.foreach("|" + EnvUtil.rubybin + " -e 'puts :foo; puts :bar; puts :baz'") {|x| a << x } # GOOD IO.write(File.join("foo", "bar.txt"), "bar") # GOOD IO.read(CONSTANT) # GOOD IO.read(CONSTANT + file) # GOOD IO.read(CONSTANT_WITH_FREEZE) # GOOD IO.read(CONSTANT_WITH_FREEZE + file) # GOOD open.where(external: false) # GOOD - an open method is called withoout arguments open(file) # BAD - sanity check to verify that file was not mistakenly marked as sanitized end end