A Thunderbird security update has been released for Ubuntu Linux 20.04 LTS, 19.10, 18.04 LTS, and 16.04 LTS.

USN-4421-1: Thunderbird vulnerabilities

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Ubuntu Security Notice USN-4421-1
July 08, 2020

thunderbird vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 20.04 LTS
- Ubuntu 19.10
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

Several security issues were fixed in Thunderbird.

Software Description:
- thunderbird: Mozilla Open Source mail and newsgroup client

Details:

Multiple security issues were discovered in Thunderbird. If a user were
tricked in to opening a specially crafted website in a browsing context,
an attacker could potentially exploit these to cause a denial of service,
obtain sensitive information, or execute arbtirary code. (CVE-2020-12405,
CVE-2020-12406, CVE-2020-12410, CVE-2020-12417, CVE-2020-12418,
CVE-2020-12419, CVE-2020-12420)

It was discovered that Thunderbird would continue an unencrypted
connection when configured to use STARTTLS for IMAP if the server
responded with PREAUTH. A remote attacker could potentially exploit
this to perform a person-in-the-middle attack in order to obtain
sensitive information. (CVE-2020-12398)

It was discovered that NSS showed timing differences when performing DSA
signatures. An attacker could potentially exploit this to obtain private
keys using a timing attack. (CVE-2020-12399)

It was discovered that when performing add-on updates, certificate chains
not terminating with built-in roots were silently rejected. This could
result in add-ons becoming outdated. (CVE-2020-12421)

Update instructions:

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

Ubuntu 20.04 LTS:
thunderbird 1:68.10.0+build1-0ubuntu0.20.04.1

Ubuntu 19.10:
thunderbird 1:68.10.0+build1-0ubuntu0.19.10.1

Ubuntu 18.04 LTS:
thunderbird 1:68.10.0+build1-0ubuntu0.18.04.1

Ubuntu 16.04 LTS:
thunderbird 1:68.10.0+build1-0ubuntu0.16.04.1

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

References:
  https://usn.ubuntu.com/4421-1
CVE-2020-12398, CVE-2020-12399, CVE-2020-12405, CVE-2020-12406,
CVE-2020-12410, CVE-2020-12417, CVE-2020-12418, CVE-2020-12419,
CVE-2020-12420, CVE-2020-12421

Package Information:

  https://launchpad.net/ubuntu/+source/thunderbird/1:68.10.0+build1-0ubuntu0.20.04.1

  https://launchpad.net/ubuntu/+source/thunderbird/1:68.10.0+build1-0ubuntu0.19.10.1

  https://launchpad.net/ubuntu/+source/thunderbird/1:68.10.0+build1-0ubuntu0.18.04.1

  https://launchpad.net/ubuntu/+source/thunderbird/1:68.10.0+build1-0ubuntu0.16.04.1