zero-day

6 synonyms and 2 antonyms for zero-day, grouped by meaning and by how common each one is.

Noun — A flaw in software that the people who make it do not yet know about, so no fix exists at the moment it starts being used against users.

Synonyms

Rare, literary or technical

Precise, but they will stand out — check the sense before using one.

zero-day vulnerability zero-day flaw 0-day unpatched vulnerability unpatched previously unknown

Synonyms by Meaning

1. noun computing

A flaw in software that the people who make it do not yet know about, so no fix exists at the moment it starts being used against users.

“The browser maker shipped an emergency update after a zero-day was found being used against journalists.”

zero-day vulnerability zero-day flaw 0-day unpatched vulnerability

Opposites

patched vulnerability known vulnerability

2. adjective computing

Describing an attack, exploit or vulnerability of this kind, one that works against software with no fix yet available.

“The intrusion used a zero-day exploit, so up-to-date machines were affected as well.”

unpatched previously unknown

How to use zero-day

The word patterns that sound natural to a native speaker.

zero-day exploit zero-day vulnerability zero-day attack disclose a zero-day zero-day in the wild

Hyphenated as zero-day in both noun and adjective use; sometimes written 0-day in security circles. Standard in technical and news writing.

Etymology

From the count of days the maker of the software has had to fix the flaw, namely zero, because it is already being used against them by the time they learn of it.

Full origin of zero-day →

Frequently asked questions

What is the difference between a zero-day and an exploit?

A zero-day is the flaw itself, a mistake in the software that nobody has fixed yet. An exploit is the piece of code or technique that takes advantage of a flaw. A zero-day exploit is an exploit built for a flaw that has no fix available.

Why is it called zero-day?

The name counts how long the makers of the software have had to respond. Once a flaw is being used in the wild before the vendor knows of it, their head start is zero days.

Does keeping software updated protect against a zero-day?

By definition a zero-day has no update available at the time it is used, so updates cannot address it in that window. Updates matter for the much larger number of flaws that already have fixes, and they close a zero-day once a patch is finally released.

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Nearby words

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