CAS-004 Exam Dumps - CompTIA SecurityX Certification Exam

Tokenization is the best solution to protect payment card data from unauthorized disclosure when moving to the cloud. Tokenization replaces sensitive card data with unique identifiers (tokens) that have no exploitable value outside the tokenization system. Even if the data is compromised, the attacker would not obtain actual card numbers. This is in line with PCI DSS requirements for protecting payment card information. Other solutions like encryption at rest or field masking help, but tokenization provides the strongest protection by ensuring that card data is not stored at all.

Segmentation isolates the vulnerable server into a separate network segment, reducing its exposure to potential attackers. By implementing firewalls or virtual LANs (VLANs), segmentation minimizes the risk of lateral movement and external exploitation, aligning with CASP+ objective 1.3, which emphasizes implementing appropriate compensating controls to address vulnerabilities.

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Comprehensive and Detailed in-Depth Explanation:

Problem Statement:

The organization needs tosecure legacy systemswhile maintaininginterconnectivitywith deployed assets.

Legacy systems are inherentlyvulnerableand canpose risksif directly connected to critical infrastructure.

Thegoalis to minimize risks withoutbreaking connectivity.

Why the Correct Answer is D (Screened Subnet):

Ascreened subnet(often called aDMZ - Demilitarized Zone) is anetwork segmentthat isolates potentially risky systems from theinternal network.

It is typically placedbetween two firewalls:

One firewall separates the DMZ from theexternal network (internet).

The other firewall isolates the DMZ from theinternal network.

This setup allowscontrolled communicationbetween legacy systems and internal assets while minimizing risk.

Key Benefits of a Screened Subnet:

Isolation:Separates legacy systems from the critical internal network.

Controlled Access:Usesfirewall rulesto restrictinbound and outbound traffic.

Reduced Attack Surface:Limits the potential impact of acompromised legacy system.

Interconnectivity Maintenance:Enables communication withdeployed assetswithout direct exposure.

Example Scenario:

A company haslegacy industrial control systems (ICS)that need to interact withmodern monitoring tools.

Placing the ICS within ascreened subnetensures:

Data flow is regulated.

Monitoring systems can still accessICS data without risking full network exposure.

Compromise of thelegacy systemdoes not automatically mean compromise of thecore network.

Why the Other Options Are Incorrect:

A. Software-defined networking (SDN):

SDN enablesdynamic network configuration, but it does not inherentlyisolate risky legacy systems.

While it can segment traffic, it is primarily used fornetwork flexibilityandmanagement, not isolation.

B. Containerization:

Containersisolate applications, but legacy systems often run ondedicated hardware or old OS environmentsthat are not container-compatible.

This approach does not meet the requirement of keeping thesystems interconnected.

C. Air gap:

Anair gapcompletelyisolates systems from any network.

This solutionbreaks interconnectivity, making itimpracticalfor the given requirement.

Ideal forhigh-security environmentsbut not whenintercommunicationis needed.

Real-World Example:

A healthcare organization haslegacy medical devicesthat must communicate with thepatient management system.

Placing these devices in ascreened subnetallows them to interact while beingisolatedfrom thecore hospital network, minimizingcyber risk.

Visual Representation:

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[Internet]

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[Firewall 1]

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[Screened Subnet/DMZ]

/ | \

[Legacy System 1] [Legacy System 2] [Monitoring Server]

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[Firewall 2]

|

[Internal Network]

Thescreened subnetacts as abuffer zone, ensuringcontrolled communicationbetween the legacy systems and the internal network.

Extract from CompTIA SecurityX CAS-005 Study Guide:

TheCompTIA SecurityX CAS-005 Official Study Guideadvises using ascreened subnet (DMZ)when isolatinglegacy systemsthat still requirenetwork connectivity. The guide emphasizes that this approach significantlyreduces riskby minimizing theattack surfacewhile maintaining necessaryinter-system communication.

Rescanning ensures all identified vulnerabilities have been resolved and no additional changes introduced new issues. This step is critical for verifying remediation effectiveness before moving systems back into production, aligning with CASP+ objective 5.1, which involves verifying security measures during testing and evaluation phases.

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Comprehensive and Detailed in-Depth Explanation:

Context:

Confidentialityis the highest priority, as the primary goal is toprotect PII (Personally Identifiable Information).

Availabilityis the second priority, crucial due to thelow latency requirementof medical devices.

Integrityis the third priority, essential to maintain accurate patient data.

The environment consists ofon-site applicationsinteracting with medical devices, wherecloud migration is not feasibledue to latency concerns.

Why the Correct Answer is C (Enable encryption at rest on medical devices):

Sinceconfidentialityis the top priority, enablingencryption at reston devices ensures thatsensitive data is protectedeven if the devices are compromised.

Medical devices can storePII locally, andencryption at restensures that even if physical or unauthorized access occurs, the data remainsconfidential.

Encrypting data at rest mitigates the risk of data leakage in scenarios likedevice theft or unauthorized access.

Given that the primary goal isconfidentiality, this action aligns with theCIA triadpriorities mentioned.

Why the Other Options Are Incorrect:

A. Move the application server to a network load balancing cluster:

This primarily addressesavailability, notconfidentiality.

Moving to a load-balanced setup may improveuptimebut doesnot directly protect PII.

B. Move the application to a CSP (Cloud Service Provider):

While cloud migration can offerenhanced security, it contradicts thelow latency requirementfor medical devices.

Transferring sensitive healthcare data to the cloud might introducelatency issuesand compromiseavailability.

D. Install FIM (File Integrity Monitoring) on the application server:

FIM primarily addressesintegrityby detecting changes in files but doesnot protect confidentiality.

Monitoring changes to filesdoes not encrypt or secure data at rest.

Best Practice:

In healthcare environments wherePII and medical data are stored locally, always implementencryption at restto ensure data remainsprotected and confidential.

TheHIPAAregulation also mandates encryption for protectingelectronic protected health information (ePHI), reinforcing the need for this step.

Extract from CompTIA SecurityX CAS-005 Study Guide:

TheCompTIA SecurityX CAS-005 Official Study Guideemphasizes that whenconfidentialityis the highest priority,data encryption at restis essential for protectingsensitive information. In healthcare environments wherePII and medical data are involved, encryption is anon-negotiable requirementto meet compliance standards.

The code snippet presents a buffer size risk where the user input (username) is accepted without limiting the number of characters, potentially leading to buffer overflow vulnerabilities. The bestsolution is to implement input validation that limits the input to a maximum of 20 characters, matching the buffer size defined in the code. This prevents overflow attacks by ensuring that user input does not exceed the allocated memory space. Other options, like adding more parameters or allowing alphanumeric characters, do not directly address the root cause of buffer overflow vulnerabilities. CASP+ stresses the importance of proper input validation and bounds checking as critical security measures.