CompTIA CySA+ Practice Test

Which method is least effective against zero-day threats due to the nature of the attack?

1. Segmentation

2. Patching

3. Threat intelligence

4. Whitelisting

The correct answer is: Patching

Patching is considered the least effective method against zero-day threats because these vulnerabilities are unknown to the software vendor and therefore have not been identified or fixed before they are exploited. Zero-day threats take advantage of software flaws that have not yet been documented publicly or addressed in updates, meaning that there are no patches available to remediate the risks at the time of the attack. While patching is generally a critical aspect of maintaining security and can protect against known vulnerabilities, its effectiveness is undermined in the context of zero-day exploits. Since these threats exploit previously unknown security holes, organisations cannot rely on patches to defend against them until patches are developed and deployed after the vulnerability is discovered. In contrast, methods like segmentation can help contain potential breaches, threat intelligence can provide insights into emerging threats, and whitelisting can prevent unauthorized applications from executing, thereby offering more proactive protection against unknown vulnerabilities. These alternatives can play a role in minimizing the impact of a zero-day threat.