$ pip install "pip<21.1"
Successfully installed pip-21.0.1

$ pip install git+https://github.com/frenzymadness/CVE-2021-3572.git@original_version

$ pip list
Package       Version
------------- -------
cve-2021-3572 9999.0
pip           21.0.1
setuptools    56.2.0
wheel         0.36.2

$ pip install -U pip
Successfully installed pip-21.1.2

$ pip install git+https://github.com/frenzymadness/CVE-2021-3572.git@original_version

$ pip list
Package       Version
------------- -------
cve-2021-3572 1.0
pip           21.1.2
setuptools    56.2.0
wheel         0.36.2