## 3 Materials and Methods
### Vulnerability and Threat Analysis
#### 3.3.3 Threat Analysis  
Each threat addresses potential attack paths across the ground, user, and space segments, incorporating security vulnerabilities specific to the satellite network environment. The three identified threats are as follows:  
(1) Threats via the Ground Segment. The first threat in the satellite network exploits vulnerabilities in the ground segment and extends to the space segment (_MEO_, _LEO_) (Figure 3). The attacker can systematically exploit vulnerabilities at each node, potentially gaining control over the key network nodes. First, the attacker exploits the \(FW\) vulnerability to gain initial access to the network. This exploitation may facilitate a privilege escalation attack, bypassing the firewall's protections and providing a pathway to the \(RT\). Next, the attacker exploits the \(RT\) vulnerability to control network traffic, enabling the injection of malicious data or tampering with data paths. During this stage, a packet injection attack can occur, allowing the attacker to establish a foothold for further access to the \(GCS\) and gateways. Subsequently, the attacker targets the \(GCS\) to access sensitive data or manipulate the command structure. By exploiting vulnerabilities in the \(GCS\), the attacker can execute a man-in-the-middle (MITM) attack, intercepting transmitted data or modifying commands sent to satellites. The vulnerabilities in \(GW_{1}\) and \(GW_{2}\) can also be exploited by the attacker. At \(GW_{1}\), the attacker may inject malicious packets or perform a DoS attack, disrupting data transmission or blocking communication. At \(GW_{2}\), an authentication bypass attack could occur, enabling the attacker to block or modify commands sent to satellites. Finally, the attacker targets \(MEO\) and \(LEO\) satellites in the space segment. At \(MEO\) satellites, the attacker may exploit memory management vulnerabilities to disrupt the satellite command system or manipulate orbital data. During this process, a command injection attack may occur, allowing the attacker to alter the satellite's control commands. At \(LEO\) satellites, the attacker may exploit data integrity vulnerabilities to perform data tampering, potentially resulting in communication distortion and control disruption. However, to execute an actual satellite attack, the attacker must first compromise the command system, which requires compromising the satellite's physical layer and data link layer. Additionally, satellites incorporate security mechanisms, including encryption, rendering real-world attacks significantly more challenging. Nevertheless, this study assumes  
Figure 3: Threats via the ground segment. potential vulnerabilities in satellites to conduct a comprehensive security modeling of a satellite network. (2) Threats via the User Segment. The second threat in satellite networks originates from the user segment and later expands into the space segment (_MEO_, _LEO_) (Figure 4). The attacker exploits vulnerabilities in _UAAV_ and _IoT_ systems to infiltrate the network and, through this intrusion path, ultimately gains access to _MEO_ and _LEO_ satellites, the core components of the satellite network [50]. First, the attacker exploits _IoT_ vulnerabilities to obtain initial access. During this process, a privilege escalation attack enables the penetration of the IoT network. Similarly, _UAAV_s contain vulnerabilities that attackers can exploit to launch a DoS attack, disrupting communication between the _IoT_ and _UAAV_s or turning off the UAV network entirely. Next, the attacker can extend the threat to \(GW_{1}\) and \(GW_{2}\). At \(GW_{1}\), the attacker can exploit TCP/IP vulnerabilities to inject malicious packets or manipulate traffic routes. Additionally, at \(GW_{2}\), there is a risk of authentication bypass or data manipulation attacks, allowing the attacker to alter commands and data transmitted to _MEO_ and _LEO_ satellites. Finally, the threat can propagate to _MEO_ and _LEO_ satellites as it expands into the space segment.