What are the two most critical aspects of risk analysis? (Choose two)
Correct Answer: A,D
Question 383
Which of the following focuses on sustaining an organization's business functions during and after a disruption?
Correct Answer: A
Section: Risk, Response and Recovery Explanation/Reference: A business continuity plan (BCP) focuses on sustaining an organization's business functions during and after a disruption. Information systems are considered in the BCP only in terms of their support to the larger business processes. The business recovery plan (BRP) addresses the restoration of business processes after an emergency. The BRP is similar to the BCP, but it typically lacks procedures to ensure continuity of critical processes throughout an emergency or disruption. The continuity of operations plan (COOP) focuses on restoring an organization's essential functions at an alternate site and performing those functions for up to 30 days before returning to normal operations. The disaster recovery plan (DRP) applies to major, usually catastrophic events that deny access to the normal facility for an extended period. A DRP is narrower in scope than an IT contingency plan in that it does not address minor disruptions that do not require relocation. 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 8).
Question 384
Which of the following statements regarding an off-site information processing facility is TRUE?
Correct Answer: A
It is very important that the offsite has the same restrictions in order to avoide misuse. The following answers are incorrect because: It should be located in proximity to the originating site so that it can quickly be made operational is incorrect as the offsite is also subject to the same disaster as of the primary site. It should be easily identified from the outside so in the event of an emergency it can be easily found is also incorrect as it should not be easily identified to prevent intentional sabotage. Need not have the same level of environmental monitoring as the originating site since this would be cost prohibitive is also incorrect as it should be like its primary site. Reference : Information Systems Audit and Control Association, Certified Information Systems Auditor 2002 review manual, chapter 5: Disaster Recovery and Business Continuity (page 265).
Question 385
Which layer defines how packets are routed between end systems?
Correct Answer: C
Explanation/Reference: The network layer (layer 3) defines how packets are routed and relayed between end systems on the same network or on interconnected networks. Message routing, error detection and control of node traffic are managed at this level. Reference(s) used for this question: 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 82).
Question 386
In the Bell-LaPadula model, the Star-property is also called:
Correct Answer: B
The Bell-LaPadula model focuses on data confidentiality and access to classified information, in contrast to the Biba Integrity Model which describes rules for the protection of data integrity. In this formal model, the entities in an information system are divided into subjects and objects. The notion of a "secure state" is defined, and it is proven that each state transition preserves security by moving from secure state to secure state, thereby proving that the system satisfies the security objectives of the model. The Bell-LaPadula model is built on the concept of a state machine with a set of allowable states in a system. The transition from one state to another state is defined by transition functions. A system state is defined to be "secure" if the only permitted access modes of subjects to objects are in accordance with a security policy. To determine whether a specific access mode is allowed, the clearance of a subject is compared to the classification of the object (more precisely, to the combination of classification and set of compartments, making up the security level) to determine if the subject is authorized for the specific access mode. The clearance/classification scheme is expressed in terms of a lattice. The model defines two mandatory access control (MAC) rules and one discretionary access control (DAC) rule with three security properties: The Simple Security Property - a subject at a given security level may not read an object at a higher security level (no read-up). The property (read "star"-property) - a subject at a given security level must not write to any object at a lower security level (no write-down). The property is also known as the Confinement property. The Discretionary Security Property - use an access control matrix to specify the discretionary access control. The transfer of information from a high-sensitivity document to a lower-sensitivity document may happen in the Bell-LaPadula model via the concept of trusted subjects. Trusted Subjects are not restricted by the property. Untrusted subjects are. Trusted Subjects must be shown to be trustworthy with regard to the security policy. This security model is directed toward access control and is characterized by the phrase: "no read up, no write down." Compare the Biba model, the Clark-Wilson model and the Chinese Wall. With Bell-LaPadula, users can create content only at or above their own security level (i.e. secret researchers can create secret or top-secret files but may not create public files; no write-down). Conversely, users can view content only at or below their own security level (i.e. secret researchers can view public or secret files, but may not view top-secret files; no read-up). Strong Property The Strong Property is an alternative to the Property in which subjects may write to objects with only a matching security level. Thus, the write-up operation permitted in the usual Property is not present, only a write-to-same level operation. The Strong Property is usually discussed in the context of multilevel database management systems and is motivated by integrity concerns. Tranquility principle The tranquility principle of the Bell-LaPadula model states that the classification of a subject or object does not change while it is being referenced. There are two forms to the tranquility principle: the "principle of strong tranquility" states that security levels do not change during the normal operation of the system and the "principle of weak tranquility" states that security levels do not change in a way that violates the rules of a given security policy. Another interpretation of the tranquility principles is that they both apply only to the period of time during which an operation involving an object or subject is occurring. That is, the strong tranquility principle means that an object's security level/label will not change during an operation (such as read or write); the weak tranquility principle means that an object's security level/label may change in a way that does not violate the security policy during an operation. Reference(s) used for this question: http://en.wikipedia.org/wiki/Biba_Model http://en.wikipedia.org/wiki/Mandatory_access_control http://en.wikipedia.org/wiki/Discretionary_access_control http://en.wikipedia.org/wiki/Clark-Wilson_model http://en.wikipedia.org/wiki/Brewer_and_Nash_model
