A Firefox regressions update has been released for Ubuntu Linux 20.04 LTS, 18.04 LTS, and 16.04 LTS.

USN-4474-2: Firefox regressions

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Ubuntu Security Notice USN-4474-2
September 03, 2020

firefox regressions
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

USN-4474-1 caused some minor regressions in Firefox.

Software Description:
- firefox: Mozilla Open Source web browser

Details:

USN-4474-1 fixed vulnerabilities in Firefox. The update introduced various
minor regressions. This update fixes the problem.

We apologize for the inconvenience.

Original advisory details:

Multiple security issues were discovered in Firefox. If a user were
tricked in to opening a specially crafted website, an attacker could
potentially exploit these to cause a denial of service, trick the user
in to installing a malicious extension, spoof the URL bar, leak sensitive
information between origins, or execute arbitrary code. (CVE-2020-15664,
CVE-2020-15665, CVE-2020-15666, CVE-2020-15670)
It was discovered that NSS incorrectly handled certain signatures.
An attacker could possibly use this issue to expose sensitive information.
(CVE-2020-12400, CVE-2020-12401, CVE-2020-6829)
A data race was discovered when importing certificate information in to
the trust store. An attacker could potentially exploit this to cause an
unspecified impact. (CVE-2020-15668)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 20.04 LTS:
firefox 80.0.1+build1-0ubuntu0.20.04.1

Ubuntu 18.04 LTS:
firefox 80.0.1+build1-0ubuntu0.18.04.1

Ubuntu 16.04 LTS:
firefox 80.0.1+build1-0ubuntu0.16.04.1

After a standard system update you need to restart Firefox to make
all the necessary changes.

References:
  https://usn.ubuntu.com/4474-2
  https://usn.ubuntu.com/4474-1
  https://launchpad.net/bugs/1893021

Package Information:

  https://launchpad.net/ubuntu/+source/firefox/80.0.1+build1-0ubuntu0.20.04.1

  https://launchpad.net/ubuntu/+source/firefox/80.0.1+build1-0ubuntu0.18.04.1

  https://launchpad.net/ubuntu/+source/firefox/80.0.1+build1-0ubuntu0.16.04.1