A zero-day vulnerability attack is a cyberattack that exploits a previously unknown vulnerability in a software or hardware system. The term “zero-day” refers to the fact that the vulnerability is exploited on the same day it becomes known. This makes these types of attacks challenging to mitigate.
These attacks are often highly targeted and sophisticated. That’s because the attackers need to gain inside knowledge in order to recognize which vulnerabilities are yet to be patched or mid patching. Zero-day attacks can be particularly damaging, as they can bypass existing security measures and exploit systems that are otherwise considered secure.