  Quantifying vulnerabilities of network systems has been a highly
controversial issue in the fields of network security and IoT. Much research
has been conducted on this purpose; however, these have many ambiguities and
uncertainties. In this paper, we investigate the quantification of
vulnerability in the Department of Transportation (DOT) as our proof of
concept. We initiate the analysis of security requirements, using Security
Quality Requirements Engineering (SQUARE) for security requirements
elicitation. Then we apply published security standards such as NIST SP-800 and
ISO 27001 to map our security factors and sub-factors. Finally, we propose our
Multi-layered Fuzzy Logic (MFL) approach based on Goal question Metrics (GQM)
to quantify network security and IoT (Mobile Devices) vulnerability in DOT.
