Unable to use chromedriver following OS upgrade
Open system preferences, security and privacy, General tab and click "Open Anyway" or similar. It will ask for root password.

https://support.apple.com/guide/mac-help/mh11784/10.15/mac/10.15

If that doesnt work, try the following, courtesy of user365987

Open a terminal window and run this command to find the location of chromedriver:

which chromedriver



Once you find the location, open that directory with MacOS Finder.
Ctrl + Click the chromdriver file.
Select Open on shortcut menu.
Click Open on the dialog.


See Open a Mac app from an unidentified developer