COIT20262 | Advanced Network Security CQU Network Assignment| Network Security

Question 1. Analysis of Protocols with Wireshark [11 marks]

For this question you must use virtnet (as used in the workshops) to study Internet applications with Wireshark. This assumes you have already setup and are familiar with virtnet. See Moodle and workshop instructions for information on setting up and using virtnet, deploying the website, and performing the attack.

Your task is to:

• Create topology 5 in virtnet where:

• node1 will be referred to as the client o node2 will be the router

o  node3 will be the server

• Start capturing packets using tcpdump on the router (node2)

• While capturing, perform the following operations in order:

1. Start netcat TCP server using assigned port on the server (node3)

2. Start netcat TCP client on the client (node1)

3. On the client (node1) type:

My ID is

4. On the server (node3) type:

Hello . I am the server.

5. On the client (node1) type:

Goodbye server.

You need to perform steps 3-5 in the correct sequence, switching from client to server to client.

• Stop the capture and save the file as pcap

The netcat TCP server must use port 6xyz where xyz is the last three (3) digits of your student ID. For example, the netcat TCP server for student ID 12034567 would be 6567.

After performing and understanding the above steps, answer the following sub-questions

• Submit your capture file as pcap on Moodle. The single file must contain all packets of the TCP exchange using your assigned port and using your ID. [3 marks]

• • Draw a message sequence diagram that illustrates all the TCP packets generated by using netcat (do not draw any packets generated by other applications or protocols, such as ARP, DNS or SSH). A message sequence diagram uses vertical lines to represent events that happen at a computer over time (time is increasing as the line goes down). Addresses of the computers/software are given at the top of the vertical lines. Horizontal or sloped arrows are used to show messages (packets) being sent between

computers. Each arrow should be labelled with the protocol, packet type and important information of the message. Examples of message sequence diagrams are given in workshops. Note that you do not need to show the packet times, and the diagram does not have to be to scale. [3 marks]

• Based on your capture only, identify the following information, and give the packet that the information is found in. If the information is found in multiple packets, give the first packet from the capture. For example, if the information is found in packet numbers 3, 5 and 7, you would give the packet as 3. [5 marks]

Information

Value

Packet

MAC address of the client

IP address of the server

Flags for 1^st TCP segment containing data

Length of data for 2^nd TCP segment containing data

Absolute sequence number of 1^st TCP segment sent by server that contains data

                         

                                                                                                    

Question 2. Web Application Attacks [12 marks]

Using virtnet, perform an SQL injection attack on the demo grading website The general steps for performing an SQL injection attack with virtnet are described at:

However you must follow these specific steps when performing the attack:

1. Before performing the attack, add two new student users to the database with the following details:

1. New student 1: username is your ID, password is your ID

1. New student 2: username is 12039999, password is hacker

2. For both of the new students add the following courses and grades:

1. New student 1: coit20262, C

1. New student 1: coit20264, D

1. New student 2: coit20262, HD
2. New student 2: coit20264, F

3. Perform the SQL injection attack as new student 2, i.e. logged in as 12039999

4. Take a screenshot of the attacker web browser showing the web form the attacker uses to perform the attack. Make sure the screenshot clearly shows the fields/data entered by the attacker. Save the screenshot as screenshot-attack.png.

5. Take a screenshot of the attacker web browser showing a successful attack, i.e. the grades of other students. Save the screenshot as screenshot-success.png.

Answer the following questions.

• Give a general explanation of an SQL injection attack. (This explanation should NOT reference the attack you performed in virtnet; it should be for any SQL injection attack). [1 marks]

• Explain two general approaches that can be used to avoid or minimise SQL injection attacks. (This explanation should NOT reference the attack you performed in virtnet; it should be for any SQL injection attack). [2 marks]

For this specific attack on

• Explain the limitation/weakness in the MyUni website that allowed the SQL injection attack to be successful. In your explanation refer to the file(s) and line(s) of code, and give samples of the code in your answer. [2 marks]

• Explain what the attacker, 12039999, had to do in their web browser to perform the attack. In your explanation include the screenshot screenshot-attack.png and refer to the information shown in that screenshot. [2 marks]

• Submit your screenshot screenshot-attack.png as a separate file. That is, you must both embed the screenshot in the report AND submit the file separately. The reason for this is that it makes it easier for the marker in reading the report to have an embedded image, but sometimes the quality is hard to read (hence the additional file submission). [1 mark]

• Explain what the attacker, 12039999, could learn or gain from performing the SQL injection attack. In your explanation include the screenshot screenshot-success.png and refer to the information shown in that screenshot. [1 mark]

• Submit your screenshot screenshot-success.png as a separate file. [1 mark]

• Explain what the website developer could do to prevent this SQL injection attack. In your explanation, give exact code and steps the developer should use. [2 marks]

Question 3. Cryptography Concepts [9 marks]

Assume you are advising a small legal business on aspects of computer and network security. The business stores many confidential documents, and many of the communications with its clients contain confidential information. The business wants to go paper-less; that is, no paper documents stored or paper-based communications. As they have only a small number (but quite valuable and loyal) clients, the clients have agreed to participate in the paper-less communications (so long as it doesn’t introduce any significant extra cost to them).

In the following questions provide an answer that is understandable by employees of the company, and also provides technical depth such that their IT manager can implement any recommended technologies (e.g. refer to standards, protocols, algorithms or software). You are allowed to use dot points, lists and diagrams in your answers, however you should keep the answer of each part shorter than ½ a page (in some cases, the answers may be just a paragraph or two).

The company has a file server, with sufficient space to store their documents for the foreseeable future.

• Provide a general explanation of how symmetric key encryption of files or disks work. [1 mark]

• With respect to the file server, explain to the company what is full-disk encryption and file-based encryption, and explain the tradeoffs between the two approaches. Include recommended technologies. [2 marks]

The company is considering backing up the file server to a cloud storage provider.

• Explain to the company any security ramifications of this approach to backup. Include reasons why or why not there are security ramifications. (Note that you should not explain about the issues of backups or costs of cloud storage; focus only on the security ramifications). [2 marks]

The company, as well as all clients, use email software and document editing software that supports digital signatures.

• Provide a general explanation of how digital signatures work, and what problems they solve for the company. [2 marks]

• Regarding both encryption on the file server and use of digital signatures, explain to the company what keys will be in use (e.g. types of keys, who will have keys) and provide recommendations on managing, sharing and changing keys. [2 marks]

Question 4. Trojan Downloads Research [8 marks]

Many people download free or paid software from reputable sources for use on their computers and mobile devices. The sources include: app stores (Google Play, Apple App Store); software distribution sites (e.g. SourceForge, GitHub, CNET Download) and individual websites of software developers. However, there have been cases when reputable sources hosting popular software have been compromised, resulting in people downloading infected software (e.g. Trojans). For example, see stories about HandBrake video converter, Transmission BitTorrent, and Google taking down potentially harmful apps from the Play Store. Your task is to study how such reputable software sources can host malicious software, and what measures software developers and hosting sites can take to reduce infection.

Note this question refers to reputable sources of software. The question is NOT about sites or systems that often host illegal or copyrighted software (e.g. torrents, file lockers).

You must write a short report that answers the following questions:

• What are the motivations and goals of malicious users in using the above mentioned attacks? Include in your answer examples of negative impact of such attacks on users and software developers. [1 mark]

• Select two examples of real Trojans or malware distributed via reputable sources, and describe those examples. [2 marks]

• What role can file hashes, digests or signatures play in securing downloads? What are the limitations of these techniques? [2 marks]

• List and explain recommendations should be given to software developers in distributing software. [1.5 marks]

• List and explain recommendations should be given to users who download software. [1.5 marks]

You should structure your report into a section for each of the above parts.

There is no minimum/maximum length of the report. As a guide 1/3 to 1/4 pages of text for each of the above parts may be appropriate. You may draw diagrams if needed. Including pictures from other sources, or including pictures that do not help with the explanation will not gain marks and may lead to reduced marks.

You may assume the audience of the report has similar background on network security as you. You should refer to techniques and concepts covered in the unit, and give sufficient technical detail to demonstrate you understand the issues.