An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). The intermediate-level directories of the filesystem cache had the system's standard umask rather than 0o077.
https://www.oracle.com/security-alerts/cpujan2021.html
https://www.openwall.com/lists/oss-security/2020/09/01/2
https://www.djangoproject.com/weblog/2020/sep/01/security-releases/
https://usn.ubuntu.com/4479-1/
https://security.netapp.com/advisory/ntap-20200918-0004/
https://groups.google.com/forum/#%21topic/django-announce/zFCMdgUnutU
https://groups.google.com/forum/#%21topic/django-announce/Gdqn58RqIDM