ERB has an @_init deserialization guard bypass via def_module / def_method / def_class

Summary Ruby 2.7.0 before ERB 2.2.0 was published on rubygems.org introduced an @init instance variable guard in ERBresult and ERBrun to prevent code execution when an ERB object is reconstructed via Marshal.load deserialization. However, three other public methods that also evaluate @src via eva...