Shopify: App messaging can be hijacked by third-party websites

The JavaScript code at https://cdn.shopify.com/s/assets/admin/index-c6e72fa910cd0182ab1d1e67ff823fb2e6ca61745c00797769410ce01aafc4d8.js installs a message event listener to receive messages from installed apps when these apps are displayed in a frame. The following check rejects invalid event...