CSC8421 Network Security Proof Reading and Paper Editing Services

CSC8421 Network Security Assignment Solution

CSC8421 Network Security Proof Reading and Paper Editing Services


In many eyes, the home intrusion has always been physical break-ins. However, the trending fashion of having many internet connected devices in our homes have precipitated another type of intrusion. This intrusion involves one whose target is the home network and where the internet-connected devices are potentially open to compromise, this might lead to devastating consequences and loses if the information system is attacked by the intruders (cybercriminals). Following this rationale, there is a need for a defensive mechanism to prevent these intruders from gaining access into the home system.

As a prominent technique for assessing system security, a system penetration method is a method that attempts to break into the target system legally using tools and technologies that are similar to the techniques used by the cybercriminals. For the purpose of this assignment, two tools were selected based on the empirical research to assess the vulnerability of a home system. The following tools were utilized in the network assessment:


Nmap, Network Nmap, is a useful tool in penetration testing for a general purpose network scanning. It refers to a host and a network scanner which scans open, filtered or closed ports, it also has the ability to make OS assumption through packet signature [5]. The Nmap tool was used in detecting the victim machines, it utilizes the open ports, versions, and OS to exploit the network vulnerability in the victimized machines. The Nmap tool is compatible with varieties of the operating system including Linux, Windows, Mac OS X among other several platforms. It has the capability of scanning open ports using various standardized TCP packet options with numerous options of command lines [1].


Metasploit framework, on the other hand, was used to exploit development, penetration testing and almost everything that may be needed by a pen tester. Metasploit involved various key steps to exploit the system network comprising selection and configuration of the target exploit, validation to find out whether the selected system is vulnerable to the exploit, selection and configuration of payloads to be used in the exploit, selection and configuration of the encoding schema in order to ensure that the payload can easily avoid the intrusion detection system and execute the exploit finally [6].

Both Nmap and Metasploit combined together made a good team of tools which contributed a great deal during the home system network assessment [9]. Nmap provided the information regarding the victim machines with potential vulnerabilities in order to make payloads using Metasploit.

Literature review

Shah, [8] illustrate vulnerability assessment and penetration testing VAPT for cyber defense. The author expounds that this approach helps in finding the vulnerabilities in advance before a cyber-attack take place for preventing an information system from being compromised by the cyber-criminals. The VAPT consist of a step by step process with nine phases. Shah proves through her vulnerability assessment results that VAPT is a fundamental technique for the technology of cyber defense [8]. Plus, VAPT, as proposed by the author, allows a system administrator to keep sensitive information and resources from being compromised by the attackers; the technique helps in reinforcing the cybersecurity.

Goel and Mehtre [3] presents an overview of penetration testing. The authors discuss the methodology for carrying out penetration testing. According to the authors, the penetration testing methodology constitutes three phases which include penetration test penetration, the actual test, and test analysis. The following are involved in the test phase according to the authors: a gathering of information, analysis of vulnerabilities and vulnerability exploit [3]. The authors further illustrate how to apply the methodology with different tools including Nmap and Metasploit among others in a penetration test using various examples.

[2], on the other hand, investigates different tools for penetration test using Kali Linux. The authors provide a helpful overview of how to carry out different penetration test in virtualized tools, private network, and system. Their implementation also utilized Metasploit in making payloads among other tools that a pen tester may need [2]. The findings show that the proposed technique for penetration test VAPT could be utilized successfully to overcome the issues concerning cyber-attack.

Greenwald and Shanle [4], on their side, propose an approach which is consist of an automatic penetration test plan that can be executed from a remote location without any prior knowledge regarding the target system [4]. The authors further come up with a technique that helps in generating and executing the test plans remotely, this technique puts into considers the ambiguity of utilizing the remote tools both to provide pent testing action and to gain the necessary knowledge management regarding systems [4].

Penetration Test

This test involved a VNC server penetration test. In this test, Nmap was the first tool to be utilized. As discussed in the previous sections, Nmap is a security scanner which is used in discovering the hosts as well as services in the OS [2]. This tool was used in hacking the VNC server attack during a penetration test. The VNC server is always used by system administrators to control the system from a remote location. Nmap penetration tester discovered that the VNC server was running on port 5900 as shown in the following screenshot.

Figure 1: Nmap tester result

As it can be seen, more analysis needs to be done in order to find out if somebody could gain access into the system from VNC service by testing the system for a weak password [4]. At this stage, the Metasploit framework was utilized to attack the VNC service. The module that was used includes vnc_login. However, due to the reason that Metasploit does not offer a big word list, a different module list was used to increase the efficiency of the test [1].

Figure 2: VNC scanner

From the diagram above, it can be seen that the password “admin” was retrieved by Metasploit, the VNC viewer was then used to authenticate the remote host [2].

VNC vulnerability mitigation technique

This threat can get lessened through various ways including the following: first, the default ports should be changed and use a username and a password containing many special or weird characters in order to reduce the automated attacks [7]. All VNC listener ports along with any feature which is not useful should be disabled. It would be safe to block the ports which are not needed with a firewall to minimize to mitigate the risk. Another important strategy is by isolating the use of malware detective machine [10]. The VNC server should be run in a virtual machine where the folders can be limited to the specified users only. Also, when installing applications it is important that the only ones that would be used remotely are installed to mitigate the VNC vulnerability. A noteworthy strategy for mitigating VNC vulnerability risk is to always keep the malware detecting software running [7]. This will limit the attack vectors which might utilize VNC server for escalation; the remote access to a system normally give cybercriminals more even without breaking into the VNC alone.


At a glance, this report utilized various penetration testing tools including Nmap which helped in scanning the VNC ports, a Metasploit was also used in finding the vulnerabilities and weakness in the VNC server system. We also discussed the strategies for mitigating the vulnerability. The system evaluation demonstrated that Nmap and Metasploit tools are effective tools and can be used for testing vulnerabilities associated with the VNC server. However, for one to use this approach, it is important that he or she seek permission from relevant individuals.


[1] C.M., Leung. “Visual security is feeble for anti-phishing.” In Anti-counterfeiting, Security, and Identification in Communication, 2009. ASID 2009. 3rd International Conference on 2009 Aug 20 (pp. 118-123). IEEE.
[2] J., Muniz. “Web Penetration Testing with Kali Linux.” Packet Publishing Ltd; 2013 Sep 25.
[3] J.N., Goel, B.M., Mehtre. “Vulnerability assessment & penetration testing as a cyber-defense technology.” Procedia Computer Science. January 2015.
[4] L., Greenwald, R., Shanley, “Automated planning for remote penetration testing.” InMILCOM 2009-2009 IEEE Military Communications Conference 2009 Oct 18 (pp. 1-7). IEEE.
[5] N., Jain, Miao R, “Detecting attacks on data centers.” Microsoft Technology Licensing LLC, assignee. United States patent application US 14/450,954. 2016 Feb 4.
[6] P., ?isar, S.M., Cisar, I., Fürstner. “Security Assessment with Kali Linux.” Bánki Közlemények (Bánki Reports). 2018 Jan 28; 1(1):49-52.
[7] S., Mittal, “A survey of soft-error mitigation techniques for non-volatile memories.” Computers. 2017 Feb 13; 6(1):8.
[8] S., Shah. “Vulnerability assessment and penetration testing (VAPT) techniques for cyber defense.” IET-NCACNS’SGGS, Nanded. 2013.
9] Y., Malhotra. “Bridging networks, systems and controls frameworks for cyber-security curriculums and standards development.”
[10]Y., Salathan, T.T., Oh, S., Jadhav, J., Myers, J.P., Jeong, Y.H., Kim, J.N., Kim. “IoT security vulnerability: A case study of a Web camera.” In Advanced Communication Technology (ICACT), 2018 20th International Conference on 2018 Feb 11 (pp. 172-177). IEEE