The problem can be corrected by updating your system to the following package versions: Ubuntu 16.04 ESM: ca-certificates 20211016~16.04.1~esm1 In general, a standard system update will make all the necessary changes.
https://ubuntu.com/security/notices/USN-5473-2
https://ubuntu.com/security/notices/USN-5473-1
https://bugs.launchpad.net/ubuntu/+source/ca-certificates/+bug/1976631
Get the latest Linux and open source security news straight to your inbox.