is ccna certification useful

is ccna certification useful.Figure 14-11 Network Segment ExampleAn axial attack (also known as an island-crossing attack [islandhopping]) is an attack on other systems within the same network. The purpose of an axial attack is to discover systems with higher access privileges (e.g., administrator privileges). This is also known in some form as a privilege elevation attack. Having discovered other systems with access to other networks, the attacker can also open up more access to and from the network while the original vulnerability is blocked, launch other forms of attacks to discover more systems, use multiple systems as exit points from the network to hide data, and so on. It is equally important to recognize privilege escalation attacks executed within a system. Such attacks involve compromising a server with a guest account and then gaining root access in order to provide additional resource privileges on that system. Figure 14.12 shows how an attacker could launch an axial attack from a compromised system located within a trusted network. The attacker discovers a vulnerability in the operating system of an employee's laptop computer; exploits the vulnerability to install a remote access tool (Remote.AccessTool,RAT) in the operating system; and through the tool, remotely connects to the employee's laptop computer to gain unrestricted access to the trusted network. An axial attack is when the threat maker first gains access to an employee's computer, then uses that computer as the "axis" to gradually erode other systems within the same network, eventually gaining higher access to the target network.There are various ways to launch an axis attack across a network. The first method is to use existing network connections and available ports on the compromised system, essentially using the compromised system as a proxy pivot point. The attacker has some access, but can only use the TCP and UDP ports available on the compromised system. The second method is to establish a VPN connection to the trusted network on the compromised system, so that the attacker can exploit all TCP and UDP ports between the attacker's system and the VPN endpoint, thereby gaining full access to the target network.14.7 Axis Attack 503Printer NetworkFiduciary network Fiduciary networkFigure 14-12 Axis AttackFigure 14.13 shows how an attacker can use a system connected to two networks as the central axis point for launching a remote attack. In performing a network security assessment, the authors found that there are many units that are vulnerable to this type of attack, which means that the host systems in these unitsThe wireless connection to the network established through the device's Ethernet port is not disabled. Guest wireless networksThere are several methods available to defend against axial attacks. The first method is to enforce proper network access control and isolation by limiting the specific network segments that can be accessed and restricting access to only perform business-related operations within those segments. This approach can restrict the systems that an attacker uses to launch an axis attack so that they cannot access new network services by breaching other systems within the same network. Let's say that if all printers are located on a particular network segment and a particular printer is compromised, the attacker can only attack other printers within the same segment and capture traffic related to network printing. The authors found that axial attacks occur within networks where security measures are poorly implemented (e.g., all devices are placed in the same network segment and no hosts accessing the network are authenticated). In the course of the many penetration tests in which the authors have participated, it has been found that many units have left vulnerable older systems in the network segment where the administrator systems and critical systems are located. Figure 14-13 An Axis Attack Using a Compromised Host