A company that performs passive vulnerability scanning at its transit VPC has detected a vulnerability related to outdated web-server software on one of its public subnets. Which of the following can

A network-based scan actively probes the target host over the network to query service banners and version information, directly confirming whether the vulnerable software version is present without requiring agent installation or system access.

An agent-based scan requires deploying and maintaining a software agent on each target host, which introduces deployment overhead and cost not warranted for a single verification task.

A port scan identifies which ports are open but provides no information about the software version running on those ports, so it cannot confirm a vulnerability related to outdated software.

A red-team exercise simulates a full adversarial attack campaign, which is costly, time-intensive, and far exceeds the scope needed to verify a single vulnerability finding.

A credentialed scan authenticates to the target system and inspects installed package versions and configurations directly, providing high-confidence true-positive verification with significantly less effort and cost than adversarial testing methods.

A blue-team exercise focuses on defensive monitoring and incident response, not on actively probing systems to verify whether a specific vulnerability exists.

Unknown environment penetration testing is the most resource-intensive and expensive assessment type and is not appropriate for simply verifying one passive scan finding.