Using SVG filters that don't use the fixed point math implementation on a target iframe, a malicious page can extract pixel values from a targeted user. This can be used to extract history information and read text values across domains. This violates same-origin policy and leads to information disclosure. This vulnerability affects Firefox < 52, Firefox ESR < 45.8, Thunderbird < 52, and Thunderbird < 45.8.
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.