Like, I hear all the time that you shouldn’t open any ports on your networks fire wall for security reasons this and security reasons that. But what are the actual security implications/risks of forwarding a port for something like Jellyfin or a Minecraft server or something like that? Explain like im 16 (or something)
Exposing your software to the internet resulting in initial access via:
Vulnerabilities being exploited (either 0 day or unpatched)
Credential stuffing or brute forcing credentials
Then depending on the vulnerability or account compromised, access to your home network where they can move laterally and install ransomware, serve spam emails or links, or mine bit coin. These are the most common scenarios.
Best practice is to not expose ports for this reason.