Which statement best describes an intrusive NSE script?

• A. Safe NSE scripts are harmless and only collect banners.
• B. NSE scripts cannot cause disruption.
• C. Intrusive NSE scripts probe vulnerabilities or misconfigurations and may disrupt service; use in controlled environments.
• D. All NSE scripts are intrusive by design.

Answer: (C)

Intrusive NSE scripts are the ones that go beyond simple information gathering and actively probe for vulnerabilities or misconfigurations in services. Because they perform actions that can affect a target’s behavior or stability—such as attempting credential checks, configuration flaws, or vulnerability tests—they can disrupt or degrade service. That’s why they’re recommended only in controlled environments or with explicit authorization, so any potential impact is anticipated and managed.

That’s why this choice is the best: it correctly notes the probing nature of intrusive scripts and their potential to disrupt, while also advising use in a controlled setting. In contrast, safe NSE scripts are designed to minimize impact and are intended for non-destructive information collection, but they aren’t restricted to just banners, and saying they’re entirely harmless or limited to banners isn’t an accurate or complete description. The idea that NSE scripts cannot cause disruption is false, since intrusive ones can; and the claim that all NSE scripts are intrusive by design is incorrect, as many scripts are categorized as safe or non-intrusive.