The cloud-init is using predictable password. It uses andom.choice when generating random password.
lists.opensuse.org/opensuse-security-announce/2020-03/msg00042.html
access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/7.9_release_notes/index
access.redhat.com/errata/RHSA-2020:3898
access.redhat.com/security/updates/classification/#moderate
bugs.launchpad.net/ubuntu/+source/cloud-init/+bug/1860795
github.com/canonical/cloud-init/pull/204
lists.debian.org/debian-lts-announce/2020/02/msg00021.html