Electron: HTTP redirect followed into local file loader

Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 39.8.8, 40.9.0, 41.2.1, and 42.0.0-beta.3, when following HTTP redirects, net.fetch() and net.request() did not restrict which schemes a redirect could target. A remote server could redirect a request to a local resource, and if the app returns or forwards the response body, local file contents could be disclosed. Apps are only affected if they make net requests to attacker-influenced URLs with redirects followed and expose the response body. This issue is fixed in versions 39.8.8, 40.9.0, 41.2.1, and 42.0.0-beta.3.