- (Topic 6)
Which of the following countermeasures would be the most appropriate to prevent possible intrusion or damage from wardialing attacks?

1. A. Monitoring and auditing for such activity
2. B. Require user authentication
3. C. Making sure only necessary phone numbers are made public
4. D. Using completely different numbers for voice and data accesses

Correct Answer: B
Knowlege of modem numbers is a poor access control method as an attacker can discover modem numbers by dialing all numbers in a range. Requiring user authentication before remote access is granted will help in avoiding unauthorized access over a modem line.
"Monitoring and auditing for such activity" is incorrect. While monitoring and auditing can assist in detecting a wardialing attack, they do not defend against a successful wardialing attack.
"Making sure that only necessary phone numbers are made public" is incorrect. Since a wardialing attack blindly calls all numbers in a range, whether certain numbers in the range are public or not is irrelevant.
"Using completely different numbers for voice and data accesses" is incorrect. Using different number ranges for voice and data access might help prevent an attacker from stumbling across the data lines while wardialing the public voice number range but this is not an adequate countermeaure.
References: CBK, p. 214
AIO3, p. 534-535

- (Topic 6)
What type of attack involves IP spoofing, ICMP ECHO and a bounce site?

1. A. IP spoofing attack
2. B. Teardrop attack
3. C. SYN attack
4. D. Smurf attack

Correct Answer: D
A smurf attack occurs when an attacker sends a spoofed (IP spoofing) PING (ICMP ECHO) packet to the broadcast address of a large network (the bounce site). The modified packet containing the address of the target system, all devices on its local network respond with a ICMP REPLY to the target system, which is then saturated with those replies. An IP spoofing attack is used to convince a system that it is communication with a known entity that gives an intruder access. It involves modifying the source address of a packet for a trusted source's address. A teardrop attack consists of modifying the length and fragmentation offset fields in sequential IP packets so the target system becomes confused and crashes after it receives contradictory instructions on how the fragments are offset on these packets. A SYN attack is when an attacker floods a system with connection requests but does not respond when the target system replies to those requests.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3: Telecommunications and Network Security (page 76).

- (Topic 2)
One of the following assertions is NOT a characteristic of Internet Protocol Security (IPsec)

1. A. Data cannot be read by unauthorized parties
2. B. The identity of all IPsec endpoints are confirmed by other endpoints
3. C. Data is delivered in the exact order in which it is sent
4. D. The number of packets being exchanged can be counted.

Correct Answer: C
IPSec provide replay protection that ensures data is not delivered multiple times, however IPsec does not ensure that data is delivered in the exact order in which it is sent. IPSEC uses TCP and packets may be delivered out of order to the receiving side depending which route was taken by the packet.
Internet Protocol Security (IPsec) has emerged as the most commonly used network layer security control for protecting communications. IPsec is a framework of open standards for ensuring private communications over IP networks. Depending on how IPsec is implemented and configured, it can provide any combination of the following types of protection:
Confidentiality. IPsec can ensure that data cannot be read by unauthorized parties. This is accomplished by encrypting data using a cryptographic algorithm and a secret key a value known only to the two parties exchanging data. The data can only be decrypted by someone who has the secret key.
Integrity. IPsec can determine if data has been changed (intentionally or unintentionally) during transit. The integrity of data can be assured by generating a message authentication code (MAC) value, which is a cryptographic checksum of the data. If the data is altered and the MAC is recalculated, the old and new MACs will differ.
Peer Authentication. Each IPsec endpoint confirms the identity of the other IPsec endpoint with which it wishes to communicate, ensuring that the network traffic and data is being sent from the expected host.
Replay Protection. The same data is not delivered multiple times, and data is not delivered grossly out of order. However, IPsec does not ensure that data is delivered in the exact order in which it is sent.
Traffic Analysis Protection. A person monitoring network traffic does not know which parties are communicating, how often communications are occurring, or how much data is being exchanged. However, the number of packets being exchanged can be counted.
Access Control. IPsec endpoints can perform filtering to ensure that only authorized IPsec users can access particular network resources. IPsec endpoints can also allow or block certain types of network traffic, such as allowing Web server access but denying file sharing.
The following are incorrect answers because they are all features provided by IPSEC:
"Data cannot be read by unauthorized parties" is wrong because IPsec provides confidentiality through the usage of the Encapsulating Security Protocol (ESP), once encrypted the data cannot be read by unauthorized parties because they have access only to the ciphertext. This is accomplished by encrypting data using a cryptographic algorithm and a session key, a value known only to the two parties exchanging data. The data can only be decrypted by someone who has a copy of the session key.
"The identity of all IPsec endpoints are confirmed by other endpoints" is wrong because IPsec provides peer authentication: Each IPsec endpoint confirms the identity of the other IPsec endpoint with which it wishes to communicate, ensuring that the network traffic and data is being sent from the expected host.
"The number of packets being exchanged can be counted" is wrong because although IPsec provides traffic protection where a person monitoring network traffic does not know which parties are communicating, how often communications are occurring, or how much data is being exchanged, the number of packets being exchanged still can be counted.
Reference(s) used for this question:
NIST 800-77 Guide to IPsec VPNs . Pages 2-3 to 2-4

- (Topic 2)
The major objective of system configuration management is which of the following?

1. A. system maintenance.
2. B. system stability.
3. C. system operations.
4. D. system tracking.

Correct Answer: B
A major objective with Configuration Management is stability. The changes to the system are controlled so that they don't lead to weaknesses or faults in th system.
The following answers are incorrect:
system maintenance. Is incorrect because it is not the best answer. Configuration Management does control the changes to the system but it is not as important as the overall stability of the system.
system operations. Is incorrect because it is not the best answer, the overall stability of the system is much more important.
system tracking. Is incorrect because while tracking changes is important, it is not the best answer. The overall stability of the system is much more important.

- (Topic 4)
What can be best defined as the examination of threat sources against system vulnerabilities to determine the threats for a particular system in a particular operational environment?

1. A. Risk management
2. B. Risk analysis
3. C. Threat analysis
4. D. Due diligence

Correct Answer: C
Threat analysis is the examination of threat sources against system vulnerabilities to determine the threats for a particular system in a particular operational environment.
The following answers are incorrect:
Risk analysis is the process of identifying the risks to system security and determining the probability of occurrence, the resulting impact, and the additional safeguards that mitigate this impact.
Risk analysis is synonymous with risk assessment and part of risk management, which is the ongoing process of assessing the risk to mission/business as part of a risk-based approach used to determine adequate security for a system by analyzing the threats and vulnerabilities and selecting appropriate, cost-effective controls to achieve and maintain an acceptable level or risk.
Due Diligence is identifying possible risks that could affect a company based on best practices and standards.
Reference(s) used for this question:
STONEBURNER, Gary & al, National Institute of Standards and Technology (NIST), NIST Special Publication 800-27, Engineering Principles for Information Technology Security (A Baseline for Achieving Security), June 2001 (page B-3).