Guide To Operating Systems Security

Guide to Operating Systems Security 0-619-16040-3

Guide to Operating Systems Security Chapter 8 Solutions

Answers to the Chapter 8 Review Questions

1. The managers at your company have decided to purchase an IEEE 802.11 network system that uses SSID. Two of the managers have talked with a wireless network salesperson who told them that SSID provides all of the security that they need. They ask for your opinion. What is your response? Answer: c. Wired Equivalent Privacy should be configured along with SSID.

2. In an IT department meeting, several of the members of the department are skeptical about the reliability of wireless communications. They recommend that you set a waiting time of 20 to 30 minutes between the time when one device initiates communication and the time when receiving devices synchronize the communication. What is your recommendation? Answer: b. Twenty to 30 minutes is too long and opens the network to a man-in-the-middle attack.

3. The automatic repeat request characteristic in the 802.11 standard relies on ______to be sure that a packet has been received. Answer: c. acknowledgment

4. Your colleague just configured 802.1x for a wireless device, by simply selecting the option to enable it. Since your colleague has never set up 802.1x before, ______. Answer: a. you recommend also configuring a form of EAP to accompany the use of 802.1x

5. In 802.11 priority-based access, which of the following is used to coordinate which station transmits at a given time? Answer: a. the access point

6. Your new wireless network comes configured by default to use open system authentication, and the advertising information on the boxes of the WNICs says that this is an important security feature. What is your response? Answer: d. Configure the network to use shared key authentication instead.

7. IEEE 802.11b communications use the ______band. Answer: b. 2.4-GHz

8. Gain is ______. (Choose all that apply.) Answer: a. the amount of amplification associated with an antenna

9. Your organization’s wireless network committee has decided to use an ESS topology. Which of the following are elements that must be used? (Choose all that apply.) Answer: a., b., and d.

10. As the result of a decision made by the security committee, your organization’s network uses smart cards. One department now wants to implement wireless networking, but the security committee (which has only one IT department person as a member) rejects this request, stating that smart cards are not compatible with wireless networks. Afterward, a member of the security committee contacts you for an official opinion of the decision. What is your response? Answer: c. Smart cards can be used when EAP is configured for wireless networking.

11. When an attacker attempts to compromise a wireless network, which of the following might the attacker take into account? (Choose all that apply.) Answer: a., b., c., and d. 1

12. Which protocol enables roaming wireless networking communications? Answer: a. the Inter-Access Point Protocol

13. Mac OS X uses which of the following wireless communications utilities? (Choose all that apply.) Answer: b. AirPort Setup Assistant

14. IEEE 802.1i security uses which of the following? (Choose all that apply.) Answer: c. and d.

15. Your company is employee-owned and works to give employees great flexibility in the workplace. Thus, some employee teams have set up their own wireless communications. What is your response? Answer: b. This approach exposes the company to the possible use of rogue access points.

16. The FCC-approved commercial bands for wireless computer networking are called ______. Answer: d. Industrial, Scientific, and Medical frequencies

17. Bluetooth uses ______. (Choose all that apply.) Answer: b. and d.

18. Where do you configure the SSID in Windows XP Professional? Answer: b. in the properties of the WNIC

19. Security for a wireless WNIC in Red Hat Linux 9.x is configured using the ______tool in the GNOME desktop. Answer: d. Network Device

20. Your manager is suspicious of 802.1x because she believes it does not enable many security options. What is your response? (Choose all the apply.) Answer: b. and c.

Hands-On Projects Tips and Solutions for Chapter 8 Project 8-1

This project enables students to learn about an important wireless resource, the WLANA web site.

In Step 2, students should see Web links such as: . Learning Center . WLAN Directory . Industry Opportunities . Events . Discussion Forum . Press Room . Request Information . Search WLANA . Small Business . Public Access . Enterprise . LAN-to-LAN Bridging

In Step 3, some example situations include: . To quickly take your network with you when you move offices . To add more workstations . For fast Internet access . To easily connect laptops to the network . To enable a network in an old building that cannot be wired

In Step 5, some example situations include: . For conference rooms in which teams meet . For sales people who work at multiple locations . For accounting audit teams and workgroups who are mobile . For cost-effective network installations Project 8-2

This project enables students to view the current focus activities of WINLAB.

In Step 3, have students check out the current focus projects. At this writing they include: . Freebits — research into radio modems . Infostation — research into developing new wireless network architectures . Ultra-Wide PHY/MAC — research on UWB propagation models . 4G Mobile Network Architectures and Protocols — research on 4G applications . Multimodal Sensor-on-Silicon — research to advance developments in multimodal wireless sensors . Dynamic Spectrum Management — research into spectrum sharing for unlicensed communications

Project 8-3

In this project, students have an opportunity to examine a WNIC, an access point, and the antennas used by each type of component.

In Step 2, students should determine the standard used by the access point, such as the 802.11 standard.

In Step 3, the antennas may be directional or omnidirectional. For the WNIC the antenna is likely to be omnidirectional. If the access point is for inside use, it is likely to be omnidirectional, or if it is for outside use it is likely to be directional. Project 8-4

In this project, students learn about Bluetooth applications through a video on the Bluetooth Web site.

In Step 4, some of the applications include: . Sharing files . Mobile headsets . Synchronizing information between portable devices . Wireless printing . Downloading files . Wireless computing during travel . Wireless computing at home . Everyday uses, such as cell phones in a grocery store . Wireless networking in the workplace

Project 8-5

Students configure the SSID for a WNIC (in Windows 2000/XP Professional) in this project. They will need access to computers equipped with WNICs.

In Step 5, sample properties might include: . Client Name . Data Rates . Infrastructure mode . Power Saving Mode(PSP) . SSID

Project 8-6

In this project, students configure 802.1x in Windows 2000 Professional and Windows XP (Professional or Home).

In Step 10, the EAP options are: . Smart Card or other Certificate . Protected EAP (PEAP) . MD5-Challenge

Project 8-7

This project gives students the opportunity to view where to configure the wireless options for a WNIC in Red Hat Linux 9.x.

In Step 5, the Mode options are: . Auto . Managed . Ad-Hoc

In Step 6, students should report that they can manually configure the SSID by clicking the Specified option and then entering the SSID.

In Step 7, students should record the transmit rate options, such as: . Auto . 11M . 5.5M . 2M . 1M

In Step 8, the WEP can be configured using the Key box. Project 8-8

In this project, students learn how to find the automated AirPort and Bluetooth utilities available for Mac OS X.

In Step 3, the utilities are: . AirPort Admin Utility . AirPort Setup Assistant . Bluetooth File Exchange . Bluetooth Serial Utility . Bluetooth Setup Assistant

Solutions to the Case Project Assignments

Lake View Chemicals produces chemicals for industrial use and for pharmaceutical companies. There are three building on their business campus. The administration building houses the company’s management, financial, and sales offices. The research building contains laboratories, scientists, and engineers. The production building is used for manufacturing chemical products and for shipping. Each building is currently networked using twisted-pair cable inside the buildings and fiber-optic cable to connect the buildings and to connect floors within the buildings.

Lake View Chemicals has patented many specialized manufacturing and chemical processes and is always researching new products. The company considers its research teams to be some of the best in this line of business, and it carefully guards its research secrets.

Some areas of the company have decided to explore the use of wireless networking. For consulting help they hire you through Aspen IT Services.

Case Project 8-1: Wireless Options for the Production Building

The staff in the production building often move from place to place and, rather than working at fixed workstations, they want to take portable computers with them as they move between different locations within the building. Create a short report that explains what you recommend.

Answer:

Students might recommend that the production building be equipped with an IEEE 802.11 network using the extended service set (ESS) topology, because it enables a more extensive area of service than the IBSS topology. Further, the ESS topology would be a multi-cell wireless LAN using as many cells as needed to provide coverage for the entire building. This design enables individuals with portable computers equipped with WNICs to roam from cell to cell. Each cell is enabled by an access point.

In order to use fewer access points and to position for higher connection speeds, the production building might deploy 802.1g devices as these mature on the market (or start with a combination of 802.1b and 802.1g devices).

Case Project 8-2: Security for the Production Building

Lake View Chemicals asks you to supplement your report in Case Study 1 by discussing the security that can be used with the Windows XP Professional and Red Hat Linux 9.x client workstations used in the Production building.

Answer:

In their reports students should note that the following security measures can be used for Windows XP Professional: . Open system authentication (weak authentication) . Shared key authentication (uses encryption keys and WEP is a form of this) . WEP (40-bit and 104-bit keys) . SSID (uses a special identifier among the communicating stations) . 802.1x (provides challenge/response authentication) . EAP and EAP-TLS (enables smart cards, and certificates, for example) . PEAP (a form of secure EAP that does not require certificates) . Authentication through RADIUS (enables the use of an authentication server)

Case Project 8-2: Security for the Production Building (Cont.)

Red Hat Linux 9.x supports the following: . Open system authentication . Shared key authentication . WEP (40-bit and 104-bit keys) . SSID . 802.1x

Case Project 8-3: Configuring Security for the Production Building

The IT staff that supports the Production Building is not sure how to configure WNIC security in Windows XP Professional and in Red Hat Linux 9.x. Create a brief report that shows how to configure the WNIC security in each operating system.

Answer:

Security for a WNIC in Windows XP Professional is configured in the properties of the WNIC, such as using the following general steps: 1. Click Start, right-click My Computer, and click Manage. 2. Click Device Manager in the tree. 3. Double-click Network adapters. 4. Right-click the wireless adapter and click Properties. 5. Click the Advanced tab. Configure the properties, such as the SSID. 6. It may be necessary to reboot after the changes are make.

Security for a WNIC in Red Hat Linux 9.x can be configured using the GNOME tool, Network Device Control, as follows: 1. Click Main Menu, point to System Tools, and click Network Device Control. 2. Click the Configure button. 3. Double-click the WNIC in the list of devices. 4. Click the Wireless Settings tab. 5. Configure the options on the Wireless Settings tab, such as the SSID and key. 6. Click OK. 7. Close the Network Configuration box. 8. Close the Network Device Control box.

Case Project 8-4: Wireless Networking for the Research Building

Many of the scientists and engineers want to have wireless networking for the Research Building, so they are not encumbered by cabling. Create a report showing the pros and cons of using wireless networking in this building.

Answer:

Students might compose a list of pros and cons such as the following.

Sample pros: . Wireless networking would enable more flexibility for moving around the building with portable computers and hand-held devices. . Wireless networking can save money and time for areas that are hard to cable, if there are such areas that are not yet cabled in that building. . Wireless networking might make it easier for the staff to meet and discuss ideas using their portable computers. . Scientists often move between a lab and an office or have downtime while waiting for a reaction to complete, and wireless computing would give them the option to move from place to place in these circumstances.

Sample cons: . This building houses computers that contain vital secrets. Because security can be compromised more easily on a wireless network, wireless networking is not likely to be a viable option. . If wireless networking is used, it will be important to thoroughly train this particular set of users to employ the tightest possible security across the board.

Conclusion: Given the secret nature of the work in this building, it is safest to not deploy wireless networking unless there are very compelling reasons for it, such as the inability to wire certain areas.

Case Project 8-5: Sources of Attacks

The IT Department is concerned about attacks made on wireless networks, because this company is in a very competitive business and they already have experienced problems with industrial spying. They ask you to compose a report that outlines some of the security threats to wireless networks.

Answer:

Students might begin by discussing how targets are found. Attackers use devices such as taking a portable computer around to locate a network. The portable computer might be equipped with a WNIC, specialized long- and short-range antennas, a GPS, and war-driving software. The GPS is used in combination with the war-driving software to locate the target. Once the target is located, the attacker might use wireless reception equipment and sniffer software to capture information, such as account names and passwords.

Another source of an attack is the use of a rogue access point. The access point may be put (innocently or not) on a network by an inside user. However, if no security is configured or if security is configured to enable access by an attacker, the information on that network may be compromised.

A rogue access point might be placed on a network and attached to a long-range antenna, to enable the attacker to receive information with less chance of revealing his or her presence.

Some attackers use a man-in-the middle approach to intercept communications between two WNICs, such as between an access point and a client. This approach enables the attacker to “listen” to the network connection and to possibly modify communications without anyone knowing this has happened.