When DNS over HTTPS is in use, it intentionally filters RFC1918 and related IP ranges from the responses as these do not make sense coming from a DoH resolver. However when an IPv4 address was mapped through IPv6, these addresses were erroneously let through, leading to a potential DNS Rebinding attack. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5. Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-26961 Reference (s):
- https://www.mozilla.org/security/advisories/mfsa2020-50/
- URL: https://www.mozilla.org/security/advisories/mfsa2020-50/
- https://www.mozilla.org/security/advisories/mfsa2020-51/
- URL: https://www.mozilla.org/security/advisories/mfsa2020-51/
- https://www.mozilla.org/security/advisories/mfsa2020-52/

