A Libgcrypt security updates has been released for Ubuntu Linux 18.04 LTS, 19.04, and 19.10

==========================================================================
Ubuntu Security Notice USN-4236-1
January 13, 2020

libgcrypt20 vulnerability
==========================================================================

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

- Ubuntu 19.10
- Ubuntu 19.04
- Ubuntu 18.04 LTS

Summary:

Libgcrypt could be made to expose sensitive information.

Software Description:
- libgcrypt20: LGPL Crypto library

Details:

It was discovered that Libgcrypt was susceptible to a ECDSA timing attack.
An attacker could possibly use this attack to recover sensitive
information.

Update instructions:

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

Ubuntu 19.10:
libgcrypt20 1.8.4-5ubuntu2.1

Ubuntu 19.04:
libgcrypt20 1.8.4-3ubuntu1.1

Ubuntu 18.04 LTS:
libgcrypt20 1.8.1-4ubuntu1.2

In general, a standard system update will make all the necessary changes.

References:
  https://usn.ubuntu.com/4236-1
CVE-2019-13627

Package Information:
  https://launchpad.net/ubuntu/+source/libgcrypt20/1.8.4-5ubuntu2.1
  https://launchpad.net/ubuntu/+source/libgcrypt20/1.8.4-3ubuntu1.1
  https://launchpad.net/ubuntu/+source/libgcrypt20/1.8.1-4ubuntu1.2