=========================================================================Ubuntu Security Notice USN-4233-1
January 09, 2020

gnutls28 update
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

SHA1 has been marked as untrusted in GnuTLS.

Software Description:
- gnutls28: GNU TLS library

Details:

As a security improvement, this update marks SHA1 as being untrusted for
digital signature operations.

Update instructions:

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

Ubuntu 18.04 LTS:
  libgnutls30                     3.5.18-1ubuntu1.2

Ubuntu 16.04 LTS:
  libgnutls30                     3.4.10-4ubuntu1.6

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

References:
  https://ubuntu.com/security/notices/USN-4233-1
  https://launchpad.net/bugs/1858691

Package Information:
  https://launchpad.net/ubuntu/+source/gnutls28/3.5.18-1ubuntu1.2
  https://launchpad.net/ubuntu/+source/gnutls28/3.4.10-4ubuntu1.6