CVE-2020-26961 — Improperly Implemented Security Check for Standard in Mozilla Firefox
Severity
6.5MEDIUMNVD
EPSS
0.3%
top 48.98%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
Timeline
PublishedDec 9
Latest updateMay 24
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 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:NExploitability: 2.8 | Impact: 3.6
Affected Packages7 packages
🔴Vulnerability Details
3GHSA▶
GHSA-4fh9-jvf5-584j: 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↗2022-05-24
CVEList▶
CVE-2020-26961: 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↗2020-12-09
OSV▶
CVE-2020-26961: 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↗2020-12-09
📋Vendor Advisories
8Debian▶
CVE-2020-26961: firefox - When DNS over HTTPS is in use, it intentionally filters RFC1918 and related IP r...↗2020