pam-python before 1.0.7-1 has an issue in regard to the default environment variable handling of Python, which could allow for local root escalation in certain PAM setups.
https://www.debian.org/security/2019/dsa-4555
https://usn.ubuntu.com/4552-2/
https://usn.ubuntu.com/4552-1/
https://tracker.debian.org/news/1066790/accepted-pam-python-107-1-source-amd64-all-into-unstable/
https://sourceforge.net/p/pam-python/code/ci/0247ab687b4347cc52859ca461fb0126dd7e2ebe/
https://lists.debian.org/debian-lts-announce/2019/11/msg00020.html