SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2020-26961

This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.

MEDIUM 6.5EPSS 1.17%

Does this matter?

Lower severity and a low EPSS score (1.17%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1
6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
EPSS
1.17% probability · 66th percentile
CISA KEV
Not listed
Affected
mozilla/firefox · mozilla/firefox esr · mozilla/thunderbird
Source
security@mozilla.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.