CVE-2020-12421 — Improper Certificate Validation in Mozilla Firefox

CWE-295 — Improper Certificate ValidationCWE-296 — Improper Following of a Certificate's Chain of Trust15 documents9 sources
Severity
6.5MEDIUMNVD
OSV7.5
EPSS
1.1%
top 22.05%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
4
Mozilla FirefoxMozilla Firefox ESRMozilla Thunderbird+1 more
Timeline
PublishedJul 9
Latest updateMay 24

Description

When performing add-on updates, certificate chains terminating in non-built-in-roots were rejected (even if they were legitimately added by an administrator.) This could have caused add-ons to become out-of-date silently without notification to the user. This vulnerability affects Firefox ESR < 68.10, Firefox < 78, and Thunderbird < 68.10.0.

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 Packages9 packages

▶CVEListV5mozilla/firefoxunspecified — 78
▶NVDmozilla/firefox< 78.0
▶CVEListV5mozilla/firefox_esrunspecified — 68.10
▶NVDmozilla/firefox_esr< 68.10.0
▶Ubuntumozilla/firefox< 78.0.1+build1-0ubuntu0.16.04.1+2

Also affects: Ubuntu Linux 16.04, 18.04, 19.10, 20.04

🔴Vulnerability Details

5
GHSA
GHSA-476g-xp34-4rj3: When performing add-on updates, certificate chains terminating in non-built-in-roots were rejected (even if they were legitimately added by an adminis↗2022-05-24
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CVEList
CVE-2020-12421: When performing add-on updates, certificate chains terminating in non-built-in-roots were rejected (even if they were legitimately added by an adminis↗2020-07-09
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OSV
CVE-2020-12421: When performing add-on updates, certificate chains terminating in non-built-in-roots were rejected (even if they were legitimately added by an adminis↗2020-07-09
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OSV
thunderbird vulnerabilities↗2020-07-08
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OSV
firefox vulnerabilities↗2020-07-02
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📋Vendor Advisories

8
Ubuntu
Thunderbird vulnerabilities↗2020-07-08
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Ubuntu
Firefox vulnerabilities↗2020-07-02
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Red Hat
Mozilla: Add-On updates did not respect the same certificate trust rules as software updates↗2020-06-30
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Debian
CVE-2020-12421: firefox - When performing add-on updates, certificate chains terminating in non-built-in-r...↗2020
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Mozilla
Mozilla Foundation Security Advisory 2020-29: CVE-2020-12421↗
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💬Community

1
Bugzilla
CVE-2020-12421 Mozilla: Add-On updates did not respect the same certificate trust rules as software updates↗2020-07-01
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CVE-2020-12421 — Improper Certificate Validation | cvebase