shopify-scripts: Denial of service (segfault) due to null pointer dereference in mrb_obj_instance_eval

Introduction ============ Provided PoC segfaults at mrbobjinstanceeval due to null pointer dereference. Proof of concept ================ Attached the poc. Crash report ============ ./sandbox eval.rb ./sandbox:20: BUG Segmentation fault at 0x00000000000003 ruby 2.3.1p112 2016-04-26 x8664-linux-gn...