The Vue.js Devtools extension was found to leak screenshot data back to a malicious web page via the standard `postMessage()` API. By creating a malicious web page with an iFrame targeting a sensitive resource (i.e. a locally accessible file or sensitive website), and registering a listener on the web page, the extension sent messages back to the listener, containing the base64 encoded screenshot data of the sensitive resource.
The Vue.js Devtools extension was found to leak screenshot data back to a malicious web page via the standard `postMessage()` API. By creating a malicious web page with an iFrame targeting a sensitive resource (i.e. a locally accessible file or sensitive website), and registering a listener on the web page, the extension sent messages back to the listener, containing the base64 encoded screenshot data of the sensitive resource.