A Thunderbird security update has been released for Ubuntu Linux 20.10.

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Ubuntu Security Notice USN-4647-1
November 25, 2020

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

- Ubuntu 20.10

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 across origins, bypass security restrictions,
conduct phishing attacks, conduct cross-site scripting (XSS) attacks,
bypass Content Security Policy (CSP) restrictions, conduct DNS rebinding
attacks, or execute arbitrary code.

Update instructions:

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

Ubuntu 20.10:
thunderbird 1:78.5.0+build3-0ubuntu0.20.10.1

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

References:
  https://usn.ubuntu.com/4647-1
CVE-2020-15683, CVE-2020-15969, CVE-2020-16012, CVE-2020-26950,
CVE-2020-26951, CVE-2020-26953, CVE-2020-26956, CVE-2020-26958,
CVE-2020-26959, CVE-2020-26960, CVE-2020-26961, CVE-2020-26965,
CVE-2020-26968

Package Information:

  https://launchpad.net/ubuntu/+source/thunderbird/1:78.5.0+build3-0ubuntu0.20.10.1