## 4 Devices' Vulnerabilities and Requirements
### Classification of IoT Security Attacks on Different Layers of IoT Networks
#### 4.6.1 Physical Attacks  
These attacks result from breaches to the IoT system's equipment, such as the IoT device's sensors, and attackers gain access through proximity, like inserting a USB drive. According to estimates, 70% of all cyberattacks start from the inside, whether deliberately or accidentally by humans. This attack can limit the lifetime or functionality of the hardware. We will discuss these attacks here. * Node Jamming in WSNs: A node jamming attack in WSNs is carried out by malicious nodes in the network, which interfere or disrupt or jam the radio signals used by sending useless information on the frequency band used [83]. An attacker can expel the service of the IoT device if the attacker can manage to jam the key sensor. In the case of a jamming attack, the statistical features (for instance, mean and variance) of a packet flow will fluctuate temporarily. Depending on its strength, a jamming source may be able to take down the entire system or only a small piece of it. This blocking can be temporary, periodic, or permanent. \begin{table}
\begin{tabular}{l l l l} \hline \hline
**Physical Attacks** & **Encryption Attacks** & **Network Attacks** & **Application Attacks** \\ \hline Node Jamming & Man In The Middle Attack & Traffic Analysis Attacks & Virus and Worms \\ Physical Damage & Side Channel Attacks & RFID Spoofing & Malicious Scripts \\ Node Tampering & Cryptanalysis Attacks & RFID Cloning & Spyware and Adware \\ Social Engineering & & RFID Unauthorized Access & Trojan Horse \\ Malicious Node Injection & & Man In the Middle Attack & Denial of Service \\ Sleep Derivation Attack & & Denial of Service & Firmware Hijacking \\ Malicious Code Injection & & Sinkhole Attack & Botnet Attack \\ RF Interference & & Routing Information Attack & Brute Force Password Attack \\ Tag Cloning & & Sybil Attack & Phishing Attacks \\ Eavesdropping & & Replay Attack & \\ Tag Tampering & & Hello Flood Attack & \\ Outage attack & & Blackmail Attack & \\ Object replication & & Blackhole Attack & \\ Hardware Trojan & & Wormhole Attack & \\  & & Grayhole Attack & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Attacks against the various layers of the IoT network. * Physical Damage: A physical damage attack is an attack that results in physical damage to the targeted infrastructure. The attacker can gain access to the devices by physically damaging entities of the IoT network to serve his interest. This type of attack can be avoided if the protection of the zone where IoT devices are located is strong [84]. * Node Tampering: A node tampering attack is an attack where an adversary damages a sensor node. The entire sensor node can be replaced, or a part of the hardware can be compromised. A compromised node can be created by altering or replacing a node, and the attacker can control that node. By getting access, an attacker can alter sensitive information, for example, shared cryptographic keys/credentials (if any) or routing tables or other data, as well as disrupt the functionality of higher communication levels [20; 39; 79; 85; 86]. * Social Engineering: In social engineering attacks, malicious activities are accomplished through human interactions [87]. Social engineering is the psychological manipulation to trick users of an IoT system into performing certain actions or giving away confidential information that would serve their goals. Social engineering attacks may involve one or more steps. An attacker begins by gathering the background data needed to carry out the attack, such as potential avenues of entry and inadequate security procedures. The attacker then goes about gaining the victim's trust, providing encouragement for additional behaviors that breach security principles, and obtaining the necessary information. * Malicious Node Injection: In this attack [84], the attacker physically deploys a malicious node in the IoT network, which gathers information for the attacker or modifies the communication data to pass wrong information to the other nodes.