Proxmox is open source server virtualization management software. It is a Debian-based Linux distribution and very perfect to create your Hacking Lab on your local networking.
The Metasploitable virtual machine is an intentionally vulnerable version of Ubuntu Linux designed for testing security tools and demonstrating common vulnerabilities. Never expose this VM to an untrusted network 😉 it’s very dangerous!
On my YouTube you can find a video guide about virtualization of Metasploitable on ProxMox!
Finally, you can find a list of all vulnerabilities in Metasploitable on the official Rapid7 website.