CompTIA Security+ Question E-87

A security administrator must implement a system that will support and enforce the following file system access control model:
FILE NAMESECURITY LABEL
Employees.docConfidential
Salary.xlsConfidential
OfficePhones.xlsUnclassified
PersonalPhones.xlsRestricted
Which of the following should the security administrator implement?

A. White and black listing
B. SCADA system
C. Trusted OS
D. Version control

Answer: C

Explanation:
A trusted operating system (TOS) is any operating system that meets the government’s requirements for security. Trusted OS uses a form of Mandatory access control called Multi-Level Security. The Mandatory access control (MAC) is a form of access control commonly employed by government and military environments. MAC specifies that access is granted based on a set of rules rather than at the discretion of a user. The rules that govern MAC are hierarchical in nature and are often called sensitivity labels, security domains, or classifications. MLS is an implementation of MAC that focuses on confidentiality. A Multi-Level Security operating system is able to enforce the separation of multiple classifications of information as well as manage multiple users with varying levels of information clearance. The military and intelligence community must handle and process various hierarchical levels of classified information. At the high-end there is Top Secret, followed in turn by Secret, Confidential, and Unclassified:

CompTIA Security+ Question D-67

During a recent investigation, an auditor discovered that an engineer’s compromised workstation was being used to connect to SCADA systems while the engineer was not logged in. The engineer is responsible for administering the SCADA systems and cannot be blocked from connecting to them. The SCADA systems cannot be modified without vendor approval which requires months of testing.
Which of the following is MOST likely to protect the SCADA systems from misuse?

A. Update anti-virus definitions on SCADA systems
B. Audit accounts on the SCADA systems
C. Install a firewall on the SCADA network
D. Deploy NIPS at the edge of the SCADA network

Answer: D

Explanation:
A supervisory control and data acquisition (SCADA) system is an industrial control system (ICS) that is used to control infrastructure processes, facility-based processes, or industrial processes. A network-based IPS (NIPS) is an intrusion detection and prevention system that scans network traffic in real time against a database of attack signatures. It is useful for detecting and responding to network-based attacks originating from outside the organization.

CompTIA Security+ Question D-6

Which of the following would be MOST appropriate to secure an existing SCADA system by preventing connections from unauthorized networks?

A. Implement a HIDS to protect the SCADA system
B. Implement a Layer 2 switch to access the SCADA system
C. Implement a firewall to protect the SCADA system
D. Implement a NIDS to protect the SCADA system

Answer: C

Explanation:
Firewalls manage traffic using filters, which is just a rule or set of rules. A recommended guideline for firewall rules is, “deny by default; allow by exception”. This means that if a network connection is not specifically allowed, it will be denied.