An information disclosure issue has been found in Firefox before 82.0 where if a valid external protocol handler was referenced in an image tag, the resulting broken image size could be distinguished from a broken image size of a non-existent protocol handler. This allowed an attacker to successfully probe whether an external protocol handler was registered.
An information disclosure issue has been found in Firefox before 82.0 where if a valid external protocol handler was referenced in an image tag, the resulting broken image size could be distinguished from a broken image size of a non-existent protocol handler. This allowed an attacker to successfully probe whether an external protocol handler was registered.
https://www.mozilla.org/en-US/security/advisories/mfsa2020-45/#CVE-2020-15680 https://bugzilla.mozilla.org/show_bug.cgi?id=1658881
Vulmon