The host is installed with Mozilla Firefox before 21.0, Firefox ESR 17.x before 17.0.6, Thunderbird before 17.0.6 or Thunderbird ESR 17.x before 17.0.6 and is prone to information disclosure vulnerability. A flaw is present in the applications, which fail to properly initialize data structures for the nsDOMSVGZoomEvent::mPreviousScale and nsDOMSVGZoomEvent::mNewScale functions. Successful exploitation allows attackers to obtain sensitive information from process memory via a crafted web site.