A Thunderbird security update has been released for Ubuntu Linux 21.10.

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Ubuntu Security Notice USN-5246-1
January 21, 2022

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

- Ubuntu 21.10

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 into opening a specially crafted website in a browsing context, an
attacker could potentially exploit these to cause a denial of service,
obtain sensitive information, conduct spoofing attacks, bypass security
restrictions, or execute arbitrary code. (CVE-2021-4129, CVE-2021-4140,
CVE-2021-43536, CVE-2021-43537, CVE-2021-43538, CVE-2021-43539,
CVE-2021-43541, CVE-2021-43542, CVE-2021-43543, CVE-2021-43545,
CVE-2021-43656, CVE-2022-22737, CVE-2022-22738, CVE-2022-22739,
CVE-2022-22740, CVE-2022-22741, CVE-2022-22742, CVE-2022-22743,
CVE-2022-22745, CVE-2022-22747, CVE-2022-22748, CVE-2022-22751)

It was discovered that JavaScript was unexpectedly enabled in the
composition area. An attacker could potentially exploit this in
combination with another vulnerability, with unspecified impacts.
(CVE-2021-43528)

A buffer overflow was discovered in the Matrix chat library bundled with
Thunderbird. An attacker could potentially exploit this to cause a denial
of service, or execute arbitrary code. (CVE-2021-44538)

It was discovered that Thunderbird's OpenPGP integration only considered
the inner signed message when checking signature validity in a message
that contains an additional outer MIME layer. An attacker could
potentially exploit this to trick the user into thinking that a message
has a valid signature. (CVE-2021-4126)

Update instructions:

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

Ubuntu 21.10:
thunderbird 1:91.5.0+build1-0ubuntu0.21.10.1

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

References:
  https://ubuntu.com/security/notices/USN-5246-1
CVE-2021-4126, CVE-2021-4129, CVE-2021-4140, CVE-2021-43528,
CVE-2021-43536, CVE-2021-43537, CVE-2021-43538, CVE-2021-43539,
CVE-2021-43541, CVE-2021-43542, CVE-2021-43543, CVE-2021-43545,
CVE-2021-43546, CVE-2021-44538, CVE-2022-22737, CVE-2022-22738,
CVE-2022-22739, CVE-2022-22740, CVE-2022-22741, CVE-2022-22742,
CVE-2022-22743, CVE-2022-22745, CVE-2022-22747, CVE-2022-22748,
CVE-2022-22751

Package Information:

  https://launchpad.net/ubuntu/+source/thunderbird/1:91.5.0+build1-0ubuntu0.21.10.1