CVE-2020-12421 Security feature bypass in Firefox

What is CVE-2020-12421?

CVE-2020-12421 is a medium-severity vulnerability in Canonical Ubuntu Linux, published on 9 Jul 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official 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 This could have caused add-ons to become out-of-date silently without notification to the user.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.

Weakness: CWE-295

Which versions are affected by CVE-2020-12421?

It affects 4 products.

Products include Canonical Ubuntu Linux, Mozilla Firefox, Mozilla Firefox Esr, Mozilla Thunderbird.

How do I fix CVE-2020-12421?

Upgrade to a fixed version.

Is CVE-2020-12421 being exploited?

There is no known exploitation of CVE-2020-12421 in the wild and no public exploit code.

Other vulnerabilities in Canonical Ubuntu Linux

• CVE-2020-11651 SaltStack Salt Authentication Bypass Exploited Critical 9.8
• CVE-2020-7247 OpenSMTPD Remote Code Execution Exploited Critical 9.8
• CVE-2019-16928 Exim Out-of-bounds Write Exploited Critical 9.8
• CVE-2018-6789 Exim Buffer Overflow Exploited Critical 9.8
• CVE-2015-2590 Oracle Java SE and Java SE Embedded Remote Code Execution Exploited Critical 9.8

All Canonical Ubuntu Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2020-12421, GHSA-476g-xp34-4rj3, UBUNTU-CVE-2020-12421.