CVE-2020-26961

medium

Description

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.

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1672528

https://www.mozilla.org/security/advisories/mfsa2020-50/

https://www.mozilla.org/security/advisories/mfsa2020-51/

https://www.mozilla.org/security/advisories/mfsa2020-52/

Details

Source: MITRE

Published: 2020-12-09

Updated: 2020-12-10

Risk Information

CVSS v2

Base Score: 4.3

Vector: AV:N/AC:M/Au:N/C:N/I:P/A:N

Impact Score: 2.9

Exploitability Score: 8.6

Severity: MEDIUM

CVSS v3

Base Score: 6.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Impact Score: 3.6

Exploitability Score: 2.8

Severity: MEDIUM