Mozilla Foundation Security Advisory 2016-13

Same-origin-policy violation using Service Workers with plugins

Announced
February 11, 2016
Reporter
Jason Pang
Impact
Critical
Products
Firefox
Fixed in
  • Firefox 44.0.2

Description

Jason Pang of OneSignal reported that service workers intercept responses to plugin network requests made through the browser. Plugins which make security decisions based on the content of network requests can have these decisions subverted if a service worker forges responses to those requests. For example, a forged crossdomain.xml could allow a malicious site to violate the same-origin policy using the Flash plugin.

References