In the process of implementing a network vulnerability assessment strategy for a tech company, the security analyst is confronted with the following scenarios:
1) A legacy application is discovered on the network, which no longer receives updates from the vendor.
2) Several systems in the network are found running outdated versions of web browsers prone to distributed attacks.
3) The network firewall has been configured using default settings and passwords.
4) Certain TCP/IP protocols used in the organization are inherently insecure.
The security analyst decides to use vulnerability scanning software. Which of the following limitations of vulnerability assessment should the analyst be most cautious about in this context?