OpenVAS, by Greenbone Networks, is a publicly available vulnerability scanner. Greenbone Networks has an entire Vulnerability Manager, part of which is the OpenVAS scanner. Greenbone's Vulnerability Manager is also open to the public and free to use. OpenVAS has the capabilities to perform network scans, including authenticated and unauthenticated testing.
sudo apt-get update && apt-get -y full-upgrade
sudo apt-get install gvm && openvas
gvm-setup
gvm-start