My bad, it was installed via the ondrej ppa. I should have noticed that the current versions of libssl is 1.1.0g and not 1.1.1a. I'm sorry for that.
$ apt policy libssl1.1 libssl1.1: Installed: 1.1.1a-2+ubuntu18.04.1+deb.sury.org+1 Candidate: 1.1.1a-2+ubuntu18.04.1+deb.sury.org+1 Version table: *** 1.1.1a-2+ubuntu18.04.1+deb.sury.org+1 500 500 http://ppa.launchpad.net/ondrej/php/ubuntu bionic/main amd64 Packages 100 /var/lib/dpkg/status 1.1.0g-2ubuntu4.3 500 500 http://eu-west-1.ec2.archive.ubuntu.com/ubuntu bionic-updates/main amd64 Packages 500 http://security.ubuntu.com/ubuntu bionic-security/main amd64 Packages 1.1.0g-2ubuntu4 500 500 http://eu-west-1.ec2.archive.ubuntu.com/ubuntu bionic/main amd64 Packages -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1808773 Title: python-boto: libssl1.1 dependency problems To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/python-boto/+bug/1808773/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs