Systems Security Certified Practitioner – SSCP – Question0164

Which of the following is an example of a passive attack?

A.
Denying services to legitimate users
B. Shoulder surfing
C. Brute-force password cracking
D. Smurfing

Correct Answer: B

Explanation:

Shoulder surfing is a form of a passive attack involving stealing passwords, personal identification numbers or other confidential information by looking over someone’s shoulder. All other forms of attack are active attacks, where a threat makes a modification to the system in an attempt to take advantage of a vulnerability. Source: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-Hill/Osborne, 2002, chapter 3: Security Management Practices (page 63).

Systems Security Certified Practitioner – SSCP – Question0163

Which of the following remote access authentication systems is the most robust?

A.
TACACS+
B. RADIUS
C. PAP
D. TACACS

Correct Answer: A

Explanation:

TACACS+ is a proprietary Cisco enhancement to TACACS and is more robust than RADIUS. PAP is not a remote access authentication system but a remote node security protocol. 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 122).

Systems Security Certified Practitioner – SSCP – Question0162

Which of the following is NOT an advantage that TACACS+ has over TACACS?

A.
Event logging
B. Use of two-factor password authentication
C. User has the ability to change his password
D. Ability for security tokens to be resynchronized

Correct Answer: A

Explanation:

Although TACACS+ provides better audit trails, event logging is a service that is provided with TACACS. 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 121).

Systems Security Certified Practitioner – SSCP – Question0161

Which type of attack involves impersonating a user or a system?

A.
Smurfing attack
B. Spoofing attack
C. Spamming attack
D. Sniffing attack

Correct Answer: B

Explanation:

A spoofing attack is when an attempt is made to gain access to a computer system by posing as an authorized user or system. Spamming refers to sending out or posting junk advertising and unsolicited mail. A smurf attack is a type of denial-of-service attack using PING and a spoofed address. Sniffing refers to observing packets passing on a network. 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 77).

Systems Security Certified Practitioner – SSCP – Question0160

Which of the following would be used to implement Mandatory Access Control (MAC)?

A.
Clark-Wilson Access Control
B. Role-based access control
C. Lattice-based access control
D. User dictated access control

Correct Answer: C

Explanation:

The lattice is a mechanism use to implement Mandatory Access Control (MAC)
Under Mandatory Access Control (MAC) you have: Mandatory Access Control
Under Non Discretionary Access Control (NDAC) you have: Rule-Based Access Control Role-Based Access Control
Under Discretionary Access Control (DAC) you have: Discretionary Access Control
The Lattice Based Access Control is a type of access control used to implement other access control method. A lattice is an ordered list of elements that has a least upper bound and a most lower bound. The lattice can be used for MAC, DAC, Integrity level, File Permission, and more
For example in the case of MAC, if we look at common government classifications, we have the following:
TOP SECRET
SECRET ———————–I am the user at secret
CONFIDENTIAL SENSITIVE BUT UNCLASSIFIED
UNCLASSIFIED
If you look at the diagram above where I am a user at SECRET it means that I can access document at lower classification but not document at TOP SECRET. The lattice is a list of ORDERED ELEMENT, in this case the ordered elements are classification levels. My least upper bound is SECRET and my most lower bound is UNCLASSIFIED.
However the lattice could also be used for Integrity Levels such as:
VERY HIGH
HIGH
MEDIUM ———-I am a user, process, application at the medium level
LOW
VERY LOW
In the case of of Integrity levels you have to think about TRUST. Of course if I take for example the the VISTA operating system which is based on Biba then Integrity Levels would be used. As a user having access to the system I cannot tell a process running with administrative privilege what to do. Else any users on the system could take control of the system by getting highly privilege process to do things on their behalf. So no read down would be allowed in this case and this is an example of the Biba model.
Last but not least the lattice could be use for file permissions:
RWX
RW ———User at this level
R
If I am a user with READ and WRITE (RW) access privilege then I cannot execute the file because I do not have execute permission which is the X under linux and UNIX.
Many people confuse the Lattice Model and many books says MAC = LATTICE, however the lattice can be use for other purposes.
There is also Role Based Access Control (RBAC) that exists out there. It COULD be used to simulate MAC but it is not MAC as it does not make use of Label on objects indicating sensitivity and categories. MAC also require a clearance that dominates the object.
You can get more info about RBAC at:http://csrc.nist.gov/groups/SNS/rbac/faq.html#03
Also note that many book uses the same acronym for Role Based Access Control and Rule Based Access Control which is RBAC, this can be confusing.
The proper way of writing the acronym for Rule Based Access Control is RuBAC, unfortunately it is not commonly used.
References: There is a great article on technet that talks about the lattice in VISTA: http://blogs.technet.com/b/steriley/archive/2006/07/21/442870.aspx also see: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 2: Access control systems (page 33). and http://www.microsoft-watch.com/content/vista/gaging_vistas_integrit…

Systems Security Certified Practitioner – SSCP – Question0159

Which of the following is an example of discretionary access control?

A.
Identity-based access control
B. Task-based access control
C. Role-based access control
D. Rule-based access control

Correct Answer: A

Explanation:

An identity-based access control is an example of discretionary access control that is based on an individual’s identity. Identity-based access control (IBAC) is access control based on the identity of the user (typically relayed as a characteristic of the process acting on behalf of that user) where access authorizations to specific objects are assigned based on user identity.
Rule Based Access Control (RuBAC) and Role Based Access Control (RBAC) are examples of non-discretionary access controls.
Rule-based access control is a type of non-discretionary access control because this access is determined by rules and the subject does not decide what those rules will be, the rules are uniformly applied to ALL of the users or subjects.
In general, all access control policies other than DAC are grouped in the category of non-discretionary access control (NDAC).
As the name implies, policies in this category have rules that are not established at the discretion of the user. Non-discretionary policies establish controls that cannot be changed by users, but only through administrative action.
Both Role Based Access Control (RBAC) and Rule Based Access Control (RuBAC) fall within Non Discretionary Access Control (NDAC). If it is not DAC or MAC then it is most likely NDAC.
BELOW YOU HAVE A DESCRIPTION OF THE DIFFERENT CATEGORIES:
MAC = Mandatory Access Control
Under a mandatory access control environment, the system or security administrator will define what permissions subjects have on objects. The administrator does not dictate user’s access but simply configure the proper level of access as dictated by the Data Owner.
The MAC system will look at the Security Clearance of the subject and compare it with the object sensitivity level or classification level. This is what is called the dominance relationship. The subject must DOMINATE the object sensitivity level. Which means that the subject must have a security clearance equal or higher than the object he is attempting to access.
MAC also introduce the concept of labels. Every objects will have a label attached to them indicating the classification of the object as well as categories that are used to impose the need to know (NTK) principle. Even thou a user has a security clearance of Secret it does not mean he would be able to access any Secret documents within the system. He would be allowed to access only Secret document for which he has a Need To Know, formal approval, and object where the user belong to one of the categories attached to the object.
If there is no clearance and no labels then IT IS NOT Mandatory Access Control.
Many of the other models can mimic MAC but none of them have labels and a dominance relationship so they are NOT in the MAC category.
DAC = Discretionary Access Control
DAC is also known as: Identity Based access control system.
The owner of an object is define as the person who created the object. As such the owner has the discretion to grant access to other users on the network. Access will be granted based solely on the identity of those users.
Such system is good for low level of security. One of the major problem is the fact that a user who has access to someone’s else file can further share the file with other users without the knowledge or permission of the owner of the file. Very quickly this could become the wild wild west as there is no control on the dissimination of the information.
RBAC = Role Based Access Control
RBAC is a form of Non-Discretionary access control. Role Based access control usually maps directly with the different types of jobs performed by employees within a company.
For example there might be 5 security administrator within your company. Instead of creating each of their profile one by one, you would simply create a role and assign the administrators to the role. Once an administrator has been assigned to a role, he will IMPLICITLY inherit the permissions of that role.
RBAC is great tool for environment where there is a a large rotation of employees on a daily basis such as a very large help desk for example.
RBAC or RuBAC = Rule Based Access Control
RuBAC is a form of Non-Discretionary access control.
A good example of a Rule Based access control device would be a Firewall. A single set of rules is imposed to all users attempting to connect through the firewall.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 33. and NISTIR-7316 at http://csrc.nist.gov/publications/nistir/7316/NISTIR-7316.pdf and http://itlaw.wikia.com/wiki/Identity-based_access_control

Systems Security Certified Practitioner – SSCP – Question0158

Which access control model would a lattice-based access control model be an example of?

A.
Mandatory access control.
B. Discretionary access control.
C. Non-discretionary access control.
D. Rule-based access control.

Correct Answer: A

Explanation:

In a lattice model, there are pairs of elements that have the least upper bound of values and greatest lower bound of values. In a Mandatory Access Control (MAC) model, users and data owners do not have as much freedom to determine who can access files.
TIPS FROM CLEMENT
Mandatory Access Control is in place whenever you have permissions that are being imposed on the subject and the subject cannot arbitrarily change them. When the subject/owner of the file can change permissions at will, it is discretionary access control.
Here is a breakdown largely based on explanations provided by Doug Landoll. I am reproducing below using my own word and not exactly how Doug explained it:
FIRST: The Lattice A lattice is simply an access control tool usually used to implement Mandatory Access Control (MAC) and it could also be used to implement RBAC but this is not as common. The lattice model can be used for Integrity level or file permissions as well. The lattice has a least upper bound and greatest lower bound. It makes use of pair of elements such as the subject security clearance pairing with the object sensitivity label.
SECOND: DAC (Discretionary Access Control) Let’s get into Discretionary Access Control: It is an access control method where the owner (read the creator of the object) will decide who has access at his own discretion. As we all know, users are sometimes insane. They will share their files with other users based on their identity but nothing prevent the user from further sharing it with other users on the network. Very quickly you loose control on the flow of information and who has access to what. It is used in small and friendly environment where a low level of security is all that is required.
THIRD: MAC (Mandatory Access Control)
All of the following are forms of Mandatory Access Control: Mandatory Access control (MAC) (Implemented using the lattice)
You must remember that MAC makes use of Security Clearance for the subject and also Labels will be assigned to the objects. The clearance of the Subject must dominate (be equal or higher) the clearance of the Object being accessed. The label attached to the object will indicate the sensitivity leval and the categories the object belongs to. The categories are used to implement the Need to Know.
All of the following are forms of Non Discretionary Access Control:
Role Based Access Control (RBAC) Rule Based Access Control (Think Firewall in this case)
The official ISC2 book says that RBAC (synonymous with Non Discretionary Access Control) is a form of DAC but they are simply wrong. RBAC is a form of Non Discretionary Access Control. Non Discretionary DOES NOT equal mandatory access control as there is no labels and clearance involved.
I hope this clarifies the whole drama related to what is what in the world of access control.
In the same line of taught, you should be familiar with the difference between Explicit permission (the user has his own profile) versus Implicit (the user inherit permissions by being a member of a role for example).
The following answers are incorrect: Discretionary access control. Is incorrect because in a Discretionary Access Control (DAC) model, access is restricted based on the authorization granted to the users. It is identity based access control only. It does not make use of a lattice.
Non-discretionary access control. Is incorrect because Non-discretionary Access Control (NDAC) uses the role-based access control method to determine access rights and permissions. It is often times used as a synonym to RBAC which is Role Based Access Control. The user inherit permission from the role when they are assigned into the role. This type of access could make use of a lattice but could also be implemented without the use of a lattice in some case. Mandatory Access Control was a better choice than this one, but RBAC could also make use of a lattice. The BEST answer was MAC.
Rule-based access control. Is incorrect because it is an example of a Non-discretionary Access Control (NDAC) access control mode. You have rules that are globally applied to all users. There is no such thing as a lattice being use in Rule-Based Access Control.
References:
AIOv3 Access Control (pages 161 -168) AIOv3 Security Models and Architecture (pages 291 -293)

Systems Security Certified Practitioner – SSCP – Question0157

Which of the following statements pertaining to Kerberos is false?

A.
The Key Distribution Center represents a single point of failure.
B. Kerberos manages access permissions.
C. Kerberos uses a database to keep a copy of all users' public keys.
D. Kerberos uses symmetric key cryptography.

Correct Answer: C

Explanation:

Kerberos is a trusted, credential-based, third-party authentication protocol that uses symmetric (secret) key cryptography to provide robust authentication to clients accessing services on a network.
One weakness of Kerberos is its Key Distribution Center (KDC), which represents a single point of failure. The KDC contains a database that holds a copy of all of the symmetric/secret keys for the principals.
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 2: Access control systems (page40).

Systems Security Certified Practitioner – SSCP – Question0156

Which of the following statements pertaining to using Kerberos without any extension is false?

A.
A client can be impersonated by password-guessing.
B. Kerberos is mostly a third-party authentication protocol.
C. Kerberos uses public key cryptography.
D. Kerberos provides robust authentication.

Correct Answer: C

Explanation:

Kerberos is a trusted, credential-based, third-party authentication protocol that uses symmetric (secret) key cryptography to provide robust authentication to clients accessing services on a network.
Because a client’s password is used in the initiation of the Kerberos request for the service protocol, password guessing can be used to impersonate a client.
Here is a nice overview of HOW Kerberos is implement as described in RFC 4556:
1. Introduction
The Kerberos V5 protocol [RFC4120] involves use of a trusted third party known as the Key Distribution Center (KDC) to negotiate shared session keys between clients and services and provide mutual authentication between them.
The corner-stones of Kerberos V5 are the Ticket and the Authenticator. A Ticket encapsulates a symmetric key (the ticket session key) in an envelope (a public message) intended for a specific service. The contents of the Ticket are encrypted with a symmetric key shared between the service principal and the issuing KDC. The encrypted part of the Ticket contains the client principal name, among other items. An Authenticator is a record that can be shown to have been recently generated using the ticket session key in the associated Ticket. The ticket session key is known by the client who requested the ticket. The contents of the Authenticator are encrypted with the associated ticket session key. The encrypted part of an Authenticator contains a timestamp and the client principal name, among other items.
As shown in Figure 1, below, the Kerberos V5 protocol consists of the following message exchanges between the client and the KDC, and the client and the application service:
The Authentication Service (AS) Exchange
The client obtains an “initial” ticket from the Kerberos authentication server (AS), typically a Ticket Granting Ticket (TGT). The AS-REQ message and the AS-REP message are the request and the reply message, respectively, between the client and the AS.
The Ticket Granting Service (TGS) Exchange
The client subsequently uses the TGT to authenticate and request a service ticket for a particular service, from the Kerberos ticket-granting server (TGS). The TGS-REQ message and the TGS-REP message are the request and the reply message respectively between the client and the TGS.
The Client/Server Authentication Protocol (AP) Exchange
The client then makes a request with an AP-REQ message, consisting of a service ticket and an authenticator that certifies the client’s possession of the ticket session key. The server may optionally reply with an AP-REP message. AP exchanges typically negotiate session-specific symmetric keys.
Usually, the AS and TGS are integrated in a single device also known as the KDC.
+————–+
+———>| KDC |
AS-REQ / +——-| |
/ / +————–+
//^ |
/ |AS-REP / |
| | / TGS-REQ + TGS-REP
||/ /
||/ /
| | / +———+
| |//
| |//
| |/ /
| v/ v
++——-+——+ +—————–+
| Client +————>| Application |
| | AP-REQ | Server |
| |<------------| | +---------------+ AP-REP +-----------------+ Figure 1: The Message Exchanges in the Kerberos V5 Protocol In the AS exchange, the KDC reply contains the ticket session key, among other items, that is encrypted using a key (the AS reply key) shared between the client and the KDC. The AS reply key is typically derived from the client's password for human users. Therefore, for human users, the attack resistance strength of the Kerberos protocol is no stronger than the strength of their passwords. Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 2: Access control systems (page 40). And HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-Hill/Osborne, 2002, chapter 4: Access Control (pages 147-151). and http://www.ietf.org/rfc/rfc4556.txt

Systems Security Certified Practitioner – SSCP – Question0155

In the context of access control, locks, gates, guards are examples of which of the following?

A.
Administrative controls
B. Technical controls
C. Physical controls
D. Logical controls

Correct Answer: C

Explanation:

Administrative, technical and physical controls are categories of access control mechanisms.
Logical and Technical controls are synonymous. So both of them could be eliminated as possible choices.
Physical Controls: These are controls to protect the organization’s people and physical environment, such as locks, gates, and guards. Physical controls may be called “operational controls” in some contexts.
Physical security covers a broad spectrum of controls to protect the physical assets (primarily the people) in an organization. Physical Controls are sometimes referred to as “operational” controls in some risk management frameworks. These controls range from doors, locks, and windows to environment controls, construction standards, and guards. Typically, physical security is based on the notion of establishing security zones or concentric areas within a facility that require increased security as you get closer to the valuable assets inside the facility. Security zones are the physical representation of the defense-in-depth principle discussed earlier in this chapter. Typically, security zones are associated with rooms, offices, floors, or smaller elements, such as a cabinet or storage locker. The design of the physical security controls within the facility must take into account the protection of the asset as well as the individuals working in that area.
Reference(s) used for this question:
Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 1301-1303). Auerbach Publications. Kindle Edition. and Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 1312-1318). Auerbach Publications. Kindle Edition.