Zero-day

"Okay, Sus, we've found the repo and some publicly available connections to the devices — 'The house and door' as you put it. How do we get in?" Kali was getting impatient and doubtful at the moment.

"Now we find a way to get in and start with the fuckups of the software developers."

Ethymology

The name Zero-day comes from the birth time of the vulnerability (expressed in days) concerning the release date of the software. This means that the core developers of the software have been unaware of it when deploying code to production. Since by definition it cannot be detected, most of the time the Zero-day is considered extremely dangerous.

Physiology

There is not one physiology that points to the Zero-day species and they can come in all shapes and sizes — some more dangerous, some less. Some live in the cloud servers, while others inhabit the single microchip of the released hardware.

Life cycle

What is typical of Zero-day, however, is their evolution ability, similar to the retro video game and anime series creatures called Pokémon. While all Zero-days start off as a similar entity, concerning age and stealth, when revealed they undergo instantaneous evolution. The next and final (as the scientific community now thinks it) stage is the N-day. Most of the time their lifespan becomes much shorter, shrinking to days, weeks or months, depending on the knowledge and accuracy of the software development team. In some cases, however, N-days could live for years and will seldomly be killed, but rather put to sleep. This fate was shared by the Spectre and Meltdown N-days in the series of Intel processors. Thankfully, killing them remotely by the development team would violate the user's rights and so the users have been given a choice:

let Spectre (or Meltdown) live — retain the CPU's performance but risk siphoning their data

put Spectre (or Meltdown) to sleep — downgrade the CPU's performance but have a safe data processing system

To this day, many enthusiasts of the old Intel CPU's run their retro workstations without realizing that Spectre and Meltdown are lurking in the background.

Photonic microchip by MidJourney

Symbiosis

While not engaging by themselves in nature, Zero-days often form a symbiotic relation with some help of the external force. Rootkitties have been known for decades to join several Zero-days in a commensal relationship to gain full access to the system they would be playing with. Commensalism is the prevailing type of interaction, though some researchers suggest Zero/N-days should be considered parasitic only since from the security perspective they are always harmful to the host system.