## 4 Discussion  
We present several exploitation techniques of IoST vulnerabilities, summarized in Table 2. The findings were analyzed in terms of five defined categories that were used for this review study: network topology, vulnerability, exploitation technique, impact, and security measure. As can be seen from the results, the most popular technique for compromising physically air-gapped networks is social engineering. The human factor remains the most attractive for hackers as the weakest link to expose an IP camera's security. In addition to forcing the people into changing the password, another way to help strengthen defenses for individuals is to establish procedures and protocols for accessing critical data points, including ensuring multi-level authentication or blockchain-based authentication between IoT components. In the logical air-gapped IoST network, the most popular technique is implanting a backdoor through vulnerable software, untrusted libraries or insecure firmware. This \begin{table}
\begin{tabular}{p{42.7 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt}} \hline \hline \multirow{2}{*}{\#} & **Network Topology** & **Vulnerability** & **Exploitation Technique** & **Impact (Use Case)** & **Security Measure** \\ \hline \multirow{2}{*}{1} & & Misconfiguration [61, 62] & Social Engineering [24, 52, 63, 64] & The leak of sensitive video feeds & Periodic change of passwords, physical access control [29], malware analysis sandbox [28], Telnet honeypots [31], protecting configuration files [32] \\ \cline{2-6}  & & & & Network segmentation, authentication via digital certificates [41, 42, 43], authentication via blockchain network changes monitoring using AR [30], AP setting [34, 35, 36, 37] and network behavior [39] \\ \cline{2-6}  & & & & Data infiltration and exfiltration, objects identification, privacy leakage & Signal jamming [13], window tinting [60] \\ \hline \multirow{2}{*}{4} & & Open WAF Port [13, 26, 29, 41, 55] & Cyber Kill Chain [42, 56] & Crippled 1 Tbps of data [56] & WAF-Hardening, NIDS, detecting of behavior changes using ML [53], risk assessment using ontology-based method [52] \\ \cline{2-6}  & Logical Air-Gap & OEM Firmware [13, 27, 48, 50] & Inbuilt Backdoor [7, 13, 24, 59, 65] & Corporate espionage & Next-Gen Scanner, anomaly-based AV \\ \cline{2-6}  & & Infected patch [13, 24, 29] & Supply Chain [13, 24, 66] & Access to video archive, footage & Anomaly-based AV, IDS/IPS, web application firewalls (WAF), ensuring trust relations [47] \\ \hline \hline \end{tabular}
\end{table} 
Table 2: A summary overview of exploitation techniques of IoST vulnerabilities in air-gapped networks. can be mitigated by applying dynamic and static source code analysis in conjunction with security scanning and risk assessment [67] before the product, such as an IP camera, goes onto the market. In Table 3, we present a vulnerability assessment using the Common Vulnerability Scoring System (CVSS), used for measuring the severity of vulnerability [68]. The CVSS score is commonly used to provide a point of comparison between vulnerabilities, and to prioritize the remediation of vulnerabilities. We have used the base set of metrics proposed in CVSS, which is comprised of exploitability and impact. The exploitability metric shows how much effort is required from the attacker to exploit the vulnerability and to launch the attack. We will consider models assessing the exploitability risk through such vulnerability attributes as _Attack Vector_, _Attack Complexity_, _Privileges Required_ and _User Interaction_. Attack Vectors vary on the level of access to the target system or network in order to exploit the vulnerability (i.e., inside or outside of company's network). A vulnerability in a local access vector requires a physical presence, i.e., access to the physical port of the equipment. A vulnerability in an outside access vector can be exploited remotely [69]. The vulnerabilities that can be exploited remotely over a network are generally considered more severe.