Ran into the same issue. Seems to be a known issue. https://bugs.launchpad.net/ubuntu/+source/openssl/+bug/1832919
What I did is follow the steps in comment #10.
Get into the box with vagrant ssh and then run:
sudo dpkg-reconfigure libc6
sudo dpkg --configure libssl1.1
sudo dpkg-reconfigure libssl1.1
Then run vagrant provision again and it will finish the process.