Description of problem:
running `pydoc -p` allows other local users to extract arbitrary files.

Version-Release number of selected component (if applicable):
python3-3.8.6-1.fc32.x86_64

How reproducible:
if pydoc is running on a port

Steps to Reproduce:
1. start pydoc on a port
2. as a different user guess or extract the port
3. call getfile on the server to extract arbitrary files, e.g. http://localhost:8888/getfile?key=/home/dave/.ssh/id_rsa.pub http://localhost:8888/getfile?key=/etc/shadow

Actual results:
any local user on the multi-user system can read all my keys and secrets

Expected results:
Access is prevented.

Additional info:
At least a warning should be printed, that this is insecure on multi-user systems.

python notebook works around this by providing a token that is required to access the notepad. Depending on the system being able to read arbitrary files can allow to impersonate my, by  e.g. stealing my ssh-key (if it is non-encrypted)