Domain 2: Access Control Flashcards
What does “Subject” mean in the Access Control context?
An active entity on an information system
What does “Object”mean in the access control context?
A passive data file
What is Discretionary Access Control (DAC)?
An access control method that gives subjects full control of objects they have been given access to including sharing the objects with other subjects.
What is Mandatory Access Control (MAC)?
It is a method where the system enforces access control based on subject’s clearances and object labels.
What is Role Based Access Control (RBAC)
A type of non-discretionary access control where subjects are given roles and access is granted to roles and not the individual.
What does DAC stand for in the Access Control context?
Discretionary Access Control
What does MAC stand for in the access control context?
Mandatory Access Control
What does RBAC stand for in the Access Control context?
Roles Based Access Control
What is the purpose of Access Control?
To protect the Confidentiality, Integrity, and Availability (CIA) of data.
What does CIA stand for in the Access Control context?
Confidentiality, Integrity, and Availability
Name two access control concerns.
Concern 1: Is the system flexible enough to allow users to run a wide variety of software that is not centrally controlled?
Concern 2: How to manage access control when legacy systems are running mission critical applications?
What are the three elements to the Access Control Triad?
Involves implementing three strong measures:
1: technical
2: physical
3: Administrative
Name three CIA Characteristics in the access control context.
1: All three work together to provide access control.
2: No one of the three is more important than the other two.
3: Every IT system will require a different prioritization of the three depending on the data, the user community and the required timeliness for data access.
Draw the CIA Pyramid
Confidentiality -> Disclosure
Integrity - Alteration
Availability - Destruction
What does DAD stand for in the Access Control context?
Disclosure
Alteration
Destruction
Name three examples of Disclosure from DAD.
1: Unauthorized access to the system
2: The unencrypted transmission of data across an insecure network
3: A trusted user relaying information to an unauthorized user.
Name two kinds of Alteration (DAD)
1: Accidental Alteration of data.
2: Purposeful Alteration of data.
Name on example of Destruction (DAD)
The North Korean scorched earth attack against South Korea.
What does IAAA stand for in the access control context?
Identification and Authentication
Authorization
Accountability
What does Identification mean in the IAAA context?
Identification: A claim by a subject to be somebody.
Name two characteristics of Indentification in the IAAA contex.
1: Must be unique or they cannot be accountable
2: Ideally, user names should not be descriptive: x3345 instead of Richard.howard.
What does Authentication mean in the IAAA context?
Verifying the Identification claim.
What does Authorization mean in the IAAA context?
Allowing the subject access to objects.
What does Accountability mean in the IAAA context?
Establishing the ability to determin which actions each subject performed on a system.
What does Access Creep mean in the Access Control context?
When one subject maintains old access rights as he moves from one division to another gaining additional access rights.
When can a subject and an object refere to the same thing?
The IE Browser is a Subject when it is running but is an Object when its executable is stored on the hard drive.
Name the two types of entities in Access Control
Subjects
Objects
Keep all access control examples simple by determining which elements are subjects and which elements are objects.
Name the three primary access control models
1: Discretionary Access Control (DAC)
2: Mandatory Access Control (MAC)
3: Non-Discretionary Access Control
Is any one Access Control Model
1: Discretionary Access Control (DAC)
2: Mandatory Access Control (MAC)
3: Non-Discretionary Access Control
better than the other?
No one model is better than the other, rather each model is used for a specific information security purpose.
Is Non-Discretionary Access Control a form of Mandatory Access Control (MAC)
No
What is Discretionary Access Control (DAC)?
Gives subjects full control of objects they have been given access to including sharing with other subjects.
DAC allows subjects the ability to grant other subjects access to their files (objects), change their attributes, alter them or delete them.
Name two operating systems that use Discretionary Access Control (DAC)
1: Windows
2: Linux
Name one weakness in Discretionary Access Control (DAC)
Confidentiality Protection because the system depends on user discretion; a user can mistakenly send a file to someone who has no business of seeing the information in that file.
What is Mandatory Access Control (MAC)?
A system enforced access control model based on the subject’s clearance and the object’s labels.
In Mandatory Access Control (MAC) systems, Subjects and Objects have
labels like SECRET and TOP SECRET.
In Mandatory Access Control (MAC) systems, when can a subject access an object?
A subject may access any object if the subject’s label is equal to or greater than the object’s label.
What is the main difference in who enforces access to objects between Discretionary Access Control (DAC) and Mandatory Access Control (MAC):
MAC uses the system to enforce access control based on the subject’s clearance and the object’s labels.
DAC counts on the Subject to use discretion in providing other subjects access to his objects
What part of the CIA model does Mandatory Access Control (MAC) systems focus on?
MAC systems focus on protecting Confidentiality in the CIA model.
Name two liabilities of Mandatory Access Control (MAC) systems compared to Discretionary Access Control (DAC) systems.
1: MAC systems are expensive compared to DAC. Clearing users is expensive.
2: MAC systems are difficult to implement especially when attempting to separate different confidentiality levels within the same interconnected IT system.
Name three Mandatory Access Control (MAC) systems
1: Honeywell’s SCOMP developed in conjunction with the US and the UK
2: Purple Penelope developed in conjunction with the US and the UK
3: LINUX Intrusion Detection System (Standard LINUX is DAC)
What is Non-Discretionary Access Control?
A system enforced access control model that cannot be changed at the discretion of ordinary users.
Users do not have discretion regarding the groups of objects they are allowed to access and they are unable to transfer objects to other subjects.
Is Role Based Access Control (RBAC) a type of
Non-Discretionary Access Control
or
Discretionary Access Control (DAC)
or
Mandatory Access Control (MAC)
Non-Discretionary Access Control
Name the three characteristics (Rules) of Role Based Access Control (RBAC) ?
1: Role Assignment:
2: Role Authorization:
3: Transaction Authorization:
In Role Based Access Control systems, is the Identification and Authentication process (Login) considered a transaction.
The Identification and Authentication process (Login) is not considered a transaction.
What does Role Assignement mean as the first Rule of Role Based Acces Control?
A subject can execute a transaction only if the subject has been assigned the proper role.
Subjects are grouped into roles. Users can take on only roles for which they authorized.
What does Role Authorization mean as the second rule of Role Based Access Control?
A subject’s role must be authorized.
Each role has access permissions based upon the role and not the position.
What does Transaction Authorization mean as the third rule in Role Based Access Control?
A subject can execute a transaction only if the transaction is authorized for the role.
Users can execute only transactions for which they are authorized.
Why is Role Based Access Control (RBAC) a form of Non-Discretionary Access Control and not Discretionary Access Control (DAC)?
RBAC is a type of non-discretionary access control becuase subjects do not have the discretion regarding groups of objects they are allaowed to access,and are unable to transfer objects to other subjects.
Why is Role Based Access Control (RBAC) a form of Non-Discretionary Access Control and not Mandatory Access Control (DAC)?
There is a superficial similarity between RBAC roles and traditional groups (MAC).
As normally implemented, a MAC group is a collection of users, rather than a collection of permissions
The ability to tie permissions directly to users in a group-based mechanism can be regarded as a “loophole” that makes it difficult to control user-permission relationships.
RBAC requires all access through roles, and permissions are connected only to roles, not directly to users.
What type of access control is Task Based Access Control?
Non-Discretionary Access Control
Is Content Dependent Access Control a full fledged access control system like DAC, MAC or RBAC?
No
Not full-fledged access controls like MAC and DAC but added in, like defense in depth, for extra protection.
Is Context Dependent Access Control a full fledged access control system like DAC, MAC or RBAC?
No
Not full-fledged access controls like MAC and DAC but added in, like defense in depth, for extra protection.
What is Content Dependent Access Control?
They add additional criteria beyond Identification and Authentication. They consider the actual content.
Example: Subjects can view their Timesheet but not the CEOs.
What is Context Dependent Access Controls?
Applies additional context before granting access.
Example: Login time.
What is Centralized Access Control?
Centralized Access Control concentrates access control in one logical point for a system or organization like Single Sign On.
What is Decentralized Access Control?
Decentralized Access Control (Distributed Access Control) distributes control to local sites and independent systems.
What is one advantage to Decentralized Access Control?
Provides more local power
Example: A US Soldier in a battlefield situation cannot call back to the help desk.
What is one disadvantage to Decentralized Access Control?
One risk is an inconsistent view across the organization even if there is a uniform policy.
Example: A US Soldier in a battlefield situation cannot call back to the help desk.
Can both Centralized Access Control and Decentralized Access Control support remote users authenticating to local systems.
Yes
Are DAC (Discretionary Access Control) and Decentralized Access Control the same thing?
No
Decentralized Access Control will always be spelled out in the exam.
What are the 7 Remote frameworks and protocols to support remote login?
- RADIUS
- Diameter
- TACACS
- TACACS+
- PAP
- CHAP
- Microsoft Active Directory
What does Radius stand for in the Access Control Protocols and Frameworks contrext?
Remote Authentication Dial In User Service
What two RFCs describe Radius?
RFC 2865 and 2866
What protocol and port does Radius officially use for authentication?
Radius officially uses the User Datagram Protocol (UDP) on port 1812 (authentication)
What protocol and port does Radius officially use for accounting?
Radius officially uses the User Datagram Protocol (UDP) on port 1813 (accounting).
What protocol and port does Radius unofficially use for authentication?
Some Radius systems unofficially usethe the User Datagram Protocol (UDP) on ports 1645 (authentication) a
What protocol and port does Radius unofficially use for accounting?
Some Radius systems unofficially use the User Datagram Protocol (UDP) on port 1646 (accounting).
Why do experts consider RADIUS to be an AAA system and not an IAAA?
Does not provide any Identiy function.
It does
Authenticate a subject’s credentials against an authentication database.
Authorize users by allowing specific user’s access to specific data objects.
Provide Accountability by creating a log entry for RADIUS connection made.
In Radius,request and response data is carried in what?
Attribute Value Pairs (AVP)
According to RFC 2865, what are the 8 Radius Attribute Value Pairs (AVPs)?
Access-Request
Access-Accept
Access-Reject
Accounting-Request
Accounting-Response
Access-Challenge
Status-Server (Experimental)
Status-Client (Experimental)
In Radius, how large is the field that holds Attribute Value Pairs (AVPs)?
Uses an 8-bit field for Attribute Value Pairs (AVPs) which gives a max of 256 total pairs.
Iin radius, what is the only element that is encrypted?
Radius Only encrypts the password; sends other data (ID for example) in the clear.
Name five problems with Radius.
1: Limited Accountability - just logs login transactions
2: Flexibility – limited functionality with 8 bit AVPs
3: Scalability – Decentralized nature makes it hard to scale
4: Reliability – Uses UDP TCP
5: Security – Does not encrypt everything
Whys is Diameter considered to be an improved successor to Radius?
1: Accounability Improved – more robust accounting capability
2: Flexibility Improved - 32 bit field provides for billions AVPs
3: Scalability Improved – Centralized server makes it easier to scale
4: Reliability Improved – Uses TCP
5: Security Improved –End to end encryption
What is the Draft standard that describes the Diameter protocol?
RFC 3588.
What does TACACS stand for?
Terminal Access Controller Access Control System (TACACS).
What is TACACS?
An older authentication protocol common to UNIX networks that allows a remote access server to forward a user’s logon password to an authentication server, sometimes called a TACACS daemon or simply TACACSD, to determine whether access can be allowed to a given system.
What does TACACS stand for?
Terminal Access Controller Access Control System
What port does TACACS communicate with?
UDP 49
Why is TACACS less secure than TACACS+ and Radius?
It was orignially designed to be an encryption protocol, not an authentication protcol.
Is TACACS+ backward compatible with TACACS?
No
Whys is TACACS+ more reliable than TACACS?
Because it uses TCP instead of UDP.
What port does TACACS+ communicate with?
TCP 49
Why is TACACS+ more secure than TACACS.
1: Improves password protection by allowing two-factor authentication;
Why is TACACS+ more secure than Radius?
Encrypts all data below the header (Better security than RADIUS)
Name two Sniffers.
SNORT
Cain & Abel
What does PAP stand for?
Password Authentication Protocol
What is the Password Authentication Protocol (PAP)?
The client authenticates itself by sending a user name and an (optionally encrypted) password to the server, which the server compares to its shared secrets database.
What RFC defines the Password Authentication Protocol (PAP)?
Defined by RFC 1334.
Why is security weak with the Password Authentication Protocol (PAP)?
Password are sent in the clear; Sniffers can pick them up. This technique is vulnerable to eavesdroppers who may try to obtain the password by listening in on the serial line, and to repeated trial and error attacks.
How does the Challenge Handshake Authentication Protocol (CHAP) work?
The server sends a randomly generated ``challenge’’ string to the client, along with its hostname.
The client uses the hostname to look up the appropriate secret, combines it with the challenge, and encrypts the string using a one-way hashing function.
The result is returned to the server along with the client’s hostname. The server now performs the same computation, and acknowledges the client if it arrives at the same result.
What does CHAP stand for?
Challenge Handshake Authentication Protocol (CHAP)
What RFC defines the CHallenge Handshake Authentication Protocol (CHAP)?
Defined by RFC 1994
In the Challenge Handshake Authentication Protocol (CHAP), is authentication one way or both ways?
Authentication is one waybut using the same secret, negotiating CHAP in both directions can be facilitate authentication in both directions.
Why is the Challenge Handshake Authentication Protocol (CHAP) more secure then the Password Authentication Protocol (PAP)?
Depends on a shared secret that is not sent across the wire. Provides protection against Playback Attacks since a Sniffer will not know the shared secret.
What protocol is Microsoft’s Active Directory based on?
Kerberos
What RFC describes the Kerberos protocol ?
RFC 1510
How long has Kerberos been integrated into the Windows Operating system?
Since Windows 2000
In Active Directory (Kerberos) does each domain operate in its own authentication space?
Yes
In Active Directory (Kerberos) can each domain contain different users, network assets, and data objects?
Yes
In Active Directory (Kerberos) how does Active Directory control access to data objects?
!: Users are placed into Groups
2: Each group may be granted access to various domains within the system.
In Active Directory (Kerberos), If a two-way trust is established between two domains, can users and data objects from each domain access groups belonging to either domain?
Yes
In Active Directory (Kerberos), If a one-way trust is established between two domains, can users from the trusted domain access resources in the trusting domain?
Yes
In Active Directory (Kerberos), can Trusts be either transitive or non-transitive.
Yes
In Active Directory (Kerberos), non-transitive trusts only exist between
two trust partners.and nobody else.
In Active Directory (Kerberos), transitive trusts exist between
the two partners and all of their partner domains.
What are the three concepts that affect Access Control but must be addressed by an organizations procedures:
1: Least Privilege:
2: Separation of Duties:
3: Rotation of Duties
In the Procedural Issues for Access Control context, what is Least Privilege?
Limiting the access of authorized users to data they require to perform their duties only.
In the Procedural Issues for Access Control context, what is Separation of Duties?
1: Allows an organization to maintain checks and balances among employees for privileged access.
2: Mandating that more than one person is required for a sensitive transaction.
In the Procedural Issues for Access Control context, what is a Separation of Duties example?
Nuke Control
In the Procedural Issues for Access Control context, what is Rotation of Duties?
When leadership rotates the staff through the same duties.
In the Procedural Issues for Access Control context, what risk does Rotation of Duties mitigate?
Collusion
In an Access Control context, objects have ______ for classification?
Labels
In an Access Control context, name three typical labels used by governments.
Confidential
Secret
Top Secret
In an Access Control context,
Unauthorized disclosure of which could reasonably expect to cause damage to national security.
is the definition of which label?
Unclassified
Sensitive But Unclassified (SBU):
Controlled Unclassified Information (CUI):
For Official Use Only (FOUO)
Confidential
Secret
Top Secret
Confidential
In an Access Control context,
Unauthorized disclosure of which could reasonably expect to cause serious damage to national security.
is the definition of which label?
Unclassified
Sensitive But Unclassified (SBU):
Controlled Unclassified Information (CUI):
For Official Use Only (FOUO)
Confidential
Secret
Top Secret
Secret
In an Access Control context,
Unauthorized disclosure of which could reasonably expect to cause grave damage to national security.
is the definition of which label?
Unclassified
Sensitive But Unclassified (SBU):
Controlled Unclassified Information (CUI):
For Official Use Only (FOUO)
Confidential
Secret
Top Secret
Top Secret
In an Access Control context,
Which US executive order defines classification criteria?
Executive Order 12356 – National Security Information
In an Access Control context,
Data that is not sensitive
is the definition of which label?
Unclassified
Sensitive But Unclassified (SBU):
Controlled Unclassified Information (CUI):
For Official Use Only (FOUO)
Confidential
Secret
Top Secret
Unclassified
In an Access Control context,
Sensitive but unclassified and is not a matter of national security (Example: Healthcare).
is the definition of which label?
Unclassified
Sensitive But Unclassified (SBU):
Controlled Unclassified Information (CUI):
For Official Use Only (FOUO)
Confidential
Secret
Top Secret
Sensitive But Unclassified (SBU)
In an Access Control context,
Certain types of unclassified information require access and distribution controls;
is the definition of which label?
Unclassified
Sensitive But Unclassified (SBU):
Controlled Unclassified Information (CUI):
For Official Use Only (FOUO)
Confidential
Secret
Top Secret
Controlled Unclassified Information (CUI):
In an Access Control context,
Unauthorized disclosure of which could adversely impact a person’s privacy or welfare, the conduct of Federal programs, or other programs or operations essential to the national interest.
is the definition of which label?
Unclassified
Sensitive But Unclassified (SBU):
Controlled Unclassified Information (CUI):
For Official Use Only (FOUO)
Confidential
Secret
Top Secret
For Official Use Only (FOUO):
In an Access Control context,
Labels enforce which CIA (Confidentiality, Integrity, Availability) Concept?
Kneed to Know
ot
Least Privelege
Least Privelege
In an Access Control context,
Compartments enforce which CIA (Confidentiality, Integrity, Availability) Concept?
Kneed to Know
ot
Least Privelege
Kneed to Know