## 4 Experimental Results and Discussion
### Attack Impact Metrics  
According to the security assessment results, we analyzed \(tv_{123-LEO}\), which represents the general attack trends observed across multiple scenarios. The key impact metrics, including the path length, probability, and risk, are summarized in Table 8b. Table 9 presents the security assessment of each threat vector based on attack impact metrics. To systematically assess the security improvements introduced by different countermeasures, we evaluated their impacts on attack probability reduction and risk mitigation.  
* OS Patch: Applying the OS patch mitigates host-based exploitation risks by addressing software vulnerabilities. The max probability decreases from 0.88 to 0.85, and the max risk is lowered from 5.9 to 5.8, leading to a partial reduction in security threats. However, as this does not mitigate network-layer threats, vulnerabilities such as CVE-2023-2319 (the GCS privilege escalation) remain critical risks. This vulnerability allows unauthorized system control, increasing the likelihood of command manipulation. Furthermore, protocol-layer vulnerabilities, including unauthorized command injection via the CCSDS, remain exploitable, highlighting the OS patch's limitation in securing communication channels within satellite networks. Despite a marginal reduction in attack probability, the overall risk classification remains _high_;
* Protocol Patch: The protocol patch addresses communication-based vulnerabilities, reducing the max probability to 0.78 and the max risk to 5.7 and demonstrating higher effectiveness against network-layer threats. This patch effectively mitigates CVE-2019-11815 (CCSDS stack overflow) and CVE-2018-17174 (NMEA injection), preventing attackers from exploiting protocol weaknesses to manipulate satellite transmissions. However, as it does not protect against host-based threats; adversaries can still exploit OS vulnerabilities to compromise ground stations or satellite control systems. Because of this limitation, the overall risk classification improves from _high_ to _medium_;
* Both Patches: The approach of combining the OS and protocol patches yields the most significant security improvement, reducing the max probability to 0.75 and the max risk to 5.4. This dual-layer protection mitigates multilayered-attack scenarios, where adversaries exploit both host and protocol vulnerabilities. A critical example is CVE-2022-23937 (LEO satellite command injection), which enables unauthorized satellite command execution through weaknesses in OS-based access control and protocol authentication mechanisms. By mitigating both host- and network-layer vulnerabilities, this strategy substantially reduces attack success rates. The overall risk classification improves from _high_ to _medium_, confirming its effectiveness in mitigating satellite network threats;
* CFR: CFR enhances network security by filtering malicious traffic and restricting unauthorized data flows within satellite communication channels. However, it does not eliminate underlying vulnerabilities, maintaining the max probability at 0.85 and the max risk at 5.8. For instance, attackers can still exploit CVE-2023-38346 (the MEO data corruption attack) to manipulate stored satellite data, bypassing filtering mechanisms. This demonstrates that although CFR effectively reduces the attack surface by blocking certain vectors, it does not fully mitigate risk. Consequently, the overall risk classification remains _high_.  
These findings highlight the necessity of a layered security strategy that integrates OS hardening, protocol-layer protections, and access control enforcement for effective threat mitigation. The analysis confirms that both patches provide the most effective mitigation, offering multisegment protection against host-based, protocol-based, and hybrid attack vectors. Although CFR enhances the access control, it is insufficient for mitigating advanced threats in satellite networks.