The range of zero days is not very low, but that’s a separate category:

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In short, an exploit to gain full administrator rights without user intervention (and usually without the user noticing). This is a very rare category, and if such a leak occurs, it is usually quickly corrected.

A patch can come quickly from the manufacturer/supplier, but if the company does not patch the leak in time, the zero day will remain active. A reboot is often necessary, for example, if the zero day is very deep in the system (core, kernel, firmware, etc.). So there are a lot of companies that postpone updates because they don’t want long reboots, especially if the server is running databases that need some time to become available again. You should also have a PvA noting how long the patch/reboot takes and its impact on users.

To reduce the chance of an unexpected zero-day connection (read: hacker abuse), you can do the following:

• A good firewall with IDS and/or IPS
• Tighten the rules in the firewall as much as possible; Make scoops more accurate
• Good antivirus with full automatic scans also at server and storage level
• Set fixed correction times to reduce risk
• Scan your network and Wi-Fi for strange devices and/or usage (Wireshark works great)

The world of hackers and making money by exhausting zero days is a very big world and a very large sum is paid to take control of a company or person.

It’s scary that you are actually not safe on the Internet and that you always have to be careful. Because before you know it, your data is out on the street and you have no control and no help limiting the damage. Strong passwords help, but if a hacker successfully clones a session cookie in time, they can achieve a lot more.

No matter how well you protect yourself, hackers will still be able to get in unless you stay off the internet completely. But then you can achieve very little, since the Internet is after water, the most important thing is to be able to arrange the basic things.