Provide references for CVE-2019-9803.
Where can I find more information about CVE-2019-9803?
References are available at: https://www.mozilla.org/security/advisories/mfsa2019-07/, https://bugzilla.mozilla.org/show_bug.cgi?id=1515863, https://bugzilla.mozilla.org/show_bug.cgi?id=1437009, https://w3c.github.io/webappsec-upgrade-insecure-requests/.