- (Topic 4)
When preparing a business continuity plan, who of the following is responsible for identifying and prioritizing time-critical systems?
Correct Answer:
B
Many elements of a BCP will address senior management, such as the statement of importance and priorities, the statement of organizational responsibility, and the statement of urgency and timing. Executive management staff initiates the project, gives final approval and gives ongoing support. The BCP committee directs the planning, implementation, and tests processes whereas functional business units participate in implementation and testing.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 8: Business Continuity Planning and Disaster Recovery Planning (page 275).
- (Topic 6)
What protocol is used to match an IP address to the appropriate hardware address of the packet's destination so it can be sent?
Correct Answer:
B
The Address Resolution Protocol (ARP) is used to match an IP address to an Ethernet address so the packet can be sent to the appropriate node.
Shon Harris in her book says:
MAC and IP addresses must be properly mapped so they can be correctly resolved. This happens through the Address Resolution Protocol (ARP). When the data link layer receives a frame, the network layer has already attached the destination IP address to it, but the data link layer cannot understand the IP address and thus invokes ARP for help.
ARP broadcasts a frame requesting the MAC address that corresponds with the destination IP address. Each computer on the subnet receives this broadcast frame, and all but the computer that has the requested IP address ignore it.
The computer that has the destination IP address responds with its MAC address. Now ARP knows what hardware address corresponds with that specific IP address. The data link layer takes the frame, adds the hardware address to it, and passes it on to the physical layer, which enables the frame to hit the wire and go to the destination computer.
ARP maps the hardware address and associated IP address and stores this mapping in its table for a predefined amount of time. This caching is done so that when another frame destined for the same IP address needs to hit the wire, ARP does not need to broadcast its request again. It just looks in its table for this information.
Man-In-The-Middle attack
Because ARP does not require authentication, an attacker could place bogus entries into the ARP cache of a remote host (gratuitous ARP replies) to carry out attacks, such as a man-in-the-middle attacks. This attack is called ARP poisoning.
The following answers were incorrect:
RARP is used to match an Ethernet address to an IP address.
ICMP is a management protocol whose function is to send message between network devices.
Routing tables are used by routers to choose the appropriate interface to route packets. Reference(s) used for this question:
Harris, Shon (2012-10-25). CISSP All-in-One Exam Guide, 6th Edition, Chapter 6 Telecommunications and Network Security, Pages 580-581 or on the Kindle edition look around Locations 12298-12306. McGraw-Hill. Kindle Edition.
and
Schneiter, Andrew (2013-04-15). Official (ISC)2 Guide to the CISSP CBK , Third Edition: Telecommunications and Network Security, Page 342.
- (Topic 1)
Which of the following was developed by the National Computer Security Center (NCSC) for the US Department of Defense ?
Correct Answer:
A
The Answer TCSEC; The TCSEC, frequently referred to as the Orange Book, is the centerpiece of the DoD Rainbow Series publications.
Initially issued by the National Computer Security Center (NCSC) an arm of the National Security Agency in 1983 and then updated in 1985, TCSEC was replaced with the development of the Common Criteria international standard originally published in 2005.
References:
KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, pages 197-199.
Wikepedia http://en.wikipedia.org/wiki/TCSEC
- (Topic 4)
A contingency plan should address:
Correct Answer:
D
Because it is rarely possible or cost effective to eliminate all risks, an attempt is made to reduce risks to an acceptable level through the risk assessment process. This process allows, from a set of potential risks (whether likely or not), to come up with a set of identified, possible risks.
The implementation of security controls allows reducing the identified risks to a smaller set of residual risks. Because these residual risks represent the complete set of situations that could affect system performance, the scope of the contingency plan may be reduced to address only this decreased risk set.
As a result, the contingency plan can be narrowly focused, conserving resources while ensuring an effective system recovery capability.
Source: SWANSON, Marianne, & al., National Institute of Standards and Technology (NIST), NIST Special Publication 800-34, Contingency Planning Guide for Information Technology Systems, December 2001 (page 7).
- (Topic 2)
Which of the following is best defined as a mode of system termination that automatically leaves system processes and components in a secure state when a failure occurs or is detected in a system?
Correct Answer:
C
NOTE: This question is referring to a system which is Logical/Technical, so it is in the context of a system that you must choose the right answer. This is very important to read the question carefully and to identify the context whether it is in the Physical world or in the Technical/Logical world.
RFC 2828 (Internet Security Glossary) defines fail safe as a mode of system termination that automatically leaves system processes and components in a secure state when a failure occurs or is detected in the system.
A secure state means in the Logical/Technical world that no access would be granted or no packets would be allowed to flow through the system inspecting the packets such as a firewall for example.
If the question would have made reference to a building or something specific to the Physical world then the answer would have been different. In the Physical World everything becomes open and full access would be granted. See the valid choices below for the Physical context.
Fail-safe in the physical security world is when doors are unlocked automatically in case of emergency. Used in environment where humans work around. As human safety is prime concern during Fire or other hazards.
The following were all wrong choices:
Fail-secure in the physical security world is when doors are locked automatically in case of emergency. Can be in an area like Cash Locker Room provided there should be alternative manually operated exit door in case of emergency.
Fail soft is selective termination of affected non-essential system functions and processes when a failure occurs or is detected in the system.
Fail Over is a redundancy mechanism and does not apply to this question.
There is a great post within the CCCure Forums on this specific QUESTION NO: :
saintrockz who is a long term contributor to the forums did outstanding research and you have the results below. The CCCure forum is a gold mine where thousands of QUESTION NO: s related to the CBK have been discussed.
According to the Official ISC2 Study Guide (OIG):
Fault Tolerance is defined as built-in capability of a system to provide continued correct execution in the presence of a limited number of hardware or software faults. It means a system can operate in the presence of hardware component failures. A single component failure in a fault-tolerant system will not cause a system interruption because the alternate component will take over the task transparently. As the cost of components continues to drop, and the demand for system availability increases, many non-fault-tolerant systems have redundancy built-in at the subsystem level. As a result, many non-fault-tolerant systems can tolerate hardware faults - consequently, the line between a fault-tolerant system and a non-fault-tolerant system becomes increasingly blurred.
According to Common Criteria:
Fail Secure - Failure with preservation of secure state, which requires that the TSF (TOE security functions) preserve a secure state in the face of the identified failures.
Acc. to The CISSP Prep Guide, Gold Ed.:
Fail over - When one system/application fails, operations will automatically switch to the backup system.
Fail safe - Pertaining to the automatic protection of programs and/or processing systems to maintain safety when a hardware or software failure is detected in a system.
Fail secure - The system preserves a secure state during and after identified failures occur. Fail soft - Pertaining to the selective termination of affected non-essential processing when a hardware or software failure is detected in a system.
Acc. to CISSP for Dummies:
Fail closed - A control failure that results all accesses blocked. Fail open - A control failure that results in all accesses permitted.
Failover - A failure mode where, if a hardware or software failure is detected, the system automatically transfers processing to a hot backup component, such as a clustered server. Fail-safe - A failure mode where, if a hardware or software failure is detected, program execution is terminated, and the system is protected from compromise.
Fail-soft (or resilient) - A failure mode where, if a hardware or software failure is detected, certain, noncritical processing is terminated, and the computer or network continues to
function in a degraded mode.
Fault-tolerant - A system that continues to operate following failure of a computer or network component.
It's good to differentiate this concept in Physical Security as well: Fail-safe
• Door defaults to being unlocked
• Dictated by fire codes
Fail-secure
• Door defaults to being locked
Reference(s) used for this question:
SHIREY, Robert W., RFC2828: Internet Security Glossary, may 2000.
