A Thunderbird regression update has been released for Ubuntu Linux 19.10 and 18.04 LTS

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Ubuntu Security Notice USN-4202-2
December 10, 2019

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

- Ubuntu 19.10
- Ubuntu 18.04 LTS

Summary:

USN-4202-1 caused a regression in Thunderbird.

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

Details:

USN-4202-1 fixed vulnerabilities in Thunderbird. After upgrading,
Thunderbird
created a new profile for some users. This update fixes the problem.

We apologize for the inconvenience.

Original advisory details:

It was discovered that a specially crafted S/MIME message with an inner
encryption layer could be displayed as having a valid signature in some
circumstances, even if the signer had no access to the encrypted message.
An attacker could potentially exploit this to spoof the message author.
(CVE-2019-11755)
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,
bypass security restrictions, bypass same-origin restrictions, conduct
cross-site scripting (XSS) attacks, or execute arbitrary code.
(CVE-2019-11757, CVE-2019-11758, CVE-2019-11759, CVE-2019-11760,
CVE-2019-11761, CVE-2019-11762, CVE-2019-11763, CVE-2019-11764)
A heap overflow was discovered in the expat library in Thunderbird. If a
user were tricked in to opening a specially crafted message, an attacker
could potentially exploit this to cause a denial of service, or execute
arbitrary code. (CVE-2019-15903)

Update instructions:

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

Ubuntu 19.10:
thunderbird 1:68.2.2+build1-0ubuntu0.19.10.1

Ubuntu 18.04 LTS:
thunderbird 1:68.2.2+build1-0ubuntu0.18.04.1

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

References:
https://usn.ubuntu.com/4202-2
https://usn.ubuntu.com/4202-1
https://launchpad.net/bugs/1854150

Package Information:

https://launchpad.net/ubuntu/+source/thunderbird/1:68.2.2+build1-0ubuntu0.19.10.1

https://launchpad.net/ubuntu/+source/thunderbird/1:68.2.2+build1-0ubuntu0.18.04.1