How can I be confident that my web server is safe from common outside attacks?
The other day I ran across Mozilla Observatory, which is a tool that gives developers an imperfect grade for the security quality of their website, from F to A+. This lead me to wonder if any existing tool like this exists for web servers in the cloud with SSH access. For example, if I have a machine that I SSH into as
ssh firstname.lastname@example.org, how can I test and verify that machine
126.96.36.199 is configured "correctly" from a security standpoint? Or at least, how can I ensure I'm doing the bare minimum correctly? Mozilla Observatory has an "SSH Observatory" but it is in Beta mode and does not seem very intelligible right now.
I am curious because I hear a lot about security breaches at large companies, Bitcoin miners finding improperly configured cloud servers, and similar problems that keep me up at night. I have my firewall setup on Ubuntu with
ufw and I think everything is all good but I worry there is something I am missing. The other day I was tailing the logs on my Ubuntu machine and the number of firewall blocks by UFW was staggering and a little eye-opening. It would be great if an automated tool existed that could tell me about any existing red flags without exploiting them.
In the absence of any automated tools for testing security standards on cloud servers, is there anything that is a "must have" for securing a cloud server?