Coinbase: Window.opener bug at

ID H1:181088
Type hackerone
Reporter punkrock
Modified 2016-11-28T18:17:31


Window.Opener Bug


When you open a link in a new tab ( target="_blank" ), the page that opens in a new tab can access the initial tab and change it's location using the window.opener property.

Browsers Verified In:

  • Mozilla Firefox

Steps To Reproduce:

  1. Visit
  2. In Image F133659, If you notice the links go through except "Bloomberg"

  3. Since Bloomberg works on http, If you're in the same network you can manipulate the bloomberg page and inject a script which manipulates window.opener


I understand this is very trivial to exploit and does not have very big impact