…without snark or jumping down my throat. I genuinely want to know why it’s so unsafe.
I’m running a Synology DS920+, with my DSM login exposed through a Cloudflare tunnel. I have 2FA enabled, Synology firewall enabled with these rules in place. I also have this IP blocklist enabled.
After all of this, how would someone be able to break in via the DSM login?
Because they’re being silly. There is no other public facing service more secure than a relatively modern OpenSSH.
In some instances, yes, it’s best to disable the ssh that comes with whatever NAS OS you’re running, because they often ship old code and don’t care about updates and security.
But if you’re running a relatively up to date OpenSSH and you’re using keys, not passwords, then you are as secure as you can reasonably be. There’s no math suggesting otherwise. Moving to a different port will reduce the frequency of attack, but that will have zero impact on the possibility of intrusion.
Put it this way: if relatively recent OpenSSH has a remotely exploitable vulnerability, you’ll see it on the news on TV. You’ll see it and hear about it literally everywhere. The world will stop for 24 hours and there will be widespread panic. You’ll know.
If your NAS has an exploit, you might read about it on The Register a few months later.
