How do zero-day exploits operate?

Zero-day exploits operate by targeting unknown vulnerabilities in software or hardware that have not yet been discovered or patched by the vendor. This means that when a zero-day exploit is deployed, there is no existing defense or fix available, as the vulnerabilities that are being exploited are still "zero days" old.

The significance of such exploits lies in their potential to cause damage or allow unauthorized access without any prior warning to the affected parties. Because they take advantage of flaws that are not yet publicly known, they can be particularly dangerous and effective for attackers, allowing them to penetrate systems, exfiltrate data, or execute malicious code without being detected.

In contrast, the other choices focus on aspects related to known vulnerabilities or outdated methods, which do not align with the critical characteristics of zero-day exploits.