A firefox regression fix update has been released for Ubuntu Linux 18.04 LTS, 16.04 LTS, and 14.04 LTS

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Ubuntu Security Notice USN-3761-2
September 13, 2018

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

- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS
- Ubuntu 14.04 LTS

Summary:

USN-3761-1 caused several regressions in Firefox.

Software Description:
- firefox: Mozilla Open Source web browser

Details:

USN-3761-1 fixed vulnerabilities in Firefox. The update caused several
regressions affecting spellchecker dictionaries and search engines. This
update fixes the problems.

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, or execute
arbitrary code. (CVE-2018-12375, CVE-2018-12376, CVE-2018-12377,
CVE-2018-12378)

It was discovered that if a user saved passwords before Firefox 58 and
then later set a master password, an unencrypted copy of these passwords
would still be accessible. A local user could exploit this to obtain
sensitive information. (CVE-2018-12383)

Update instructions:

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

Ubuntu 18.04 LTS:
firefox 62.0+build2-0ubuntu0.18.04.4

Ubuntu 16.04 LTS:
firefox 62.0+build2-0ubuntu0.16.04.4

Ubuntu 14.04 LTS:
firefox 62.0+build2-0ubuntu0.14.04.4

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

References:
https://usn.ubuntu.com/usn/usn-3761-2
https://usn.ubuntu.com/usn/usn-3761-1
https://launchpad.net/bugs/1791789

Package Information:
https://launchpad.net/ubuntu/+source/firefox/62.0+build2-0ubuntu0.18.04.4
https://launchpad.net/ubuntu/+source/firefox/62.0+build2-0ubuntu0.16.04.4
https://launchpad.net/ubuntu/+source/firefox/62.0+build2-0ubuntu0.14.04.4

  Firefox Regression Update for Ubuntu