In Django 2.2 before 2.2.18, 3.0 before 3.0.12, and 3.1 before 3.1.6, the django.utils.archive.extract method (used by startapp --template and startproject --template) allows directory traversal via an archive with absolute paths or relative paths with dot segments. https://nvd.nist.gov/vuln/detail/CVE-2021-3281
