QSA_New_V4 Questions and Answers

Sampling in Assessments

PCI DSS v4.0 requires assessors to ensure that sampled business facilities represent all types and locations to provide comprehensive coverage of the entity’s operations​​.

Sampling Considerations

Assessors must include facilities storing or processing cardholder data and validate controls across diverse locations.

Incorrect Options

Option A: Consistency does not ensure comprehensive representation.

Option B: PCI DSS does not mandate a 10% sample size.

Option C: It is not mandatory to review every facility storing cardholder data.

Requirement for Secure Transmission:

PCI DSS Requirement 4.1 mandates that cardholder data sent over open public networks must be protected with strong cryptographic protocols. Accepting only trusted keys ensures data integrity and prevents unauthorized access​​.

Key Validation Practices:

Trusted keys and certificates are verified to ensure authenticity. Using untrusted keys compromises the security of the encrypted communication.

Prohibited Practices:

A/D:Configuring protocols to accept all certificates or lower encryption strength violates PCI DSS encryption guidelines.

B:Proprietary protocols are not inherently compliant unless they meet strong cryptographic standards.

Testing and Verification:

Assessors verify the implementation of trusted keys by examining encryption settings, reviewing certificate chains, and conducting tests to confirm only trusted connections are accepted​​.

Segmentation Defined

PCI DSS v4.0 specifies that effective segmentation separates the CDE from out-of-scope environments, minimizing the risk of unauthorized access to cardholder data​.

Key Requirements for Segmentation

Network traffic between the CDE and out-of-scope networks must be completely prevented. This ensures that out-of-scope systems cannot introduce risks to the CDE.

Methods like firewalls, ACLs (Access Control Lists), and other technologies may be used to enforce segmentation.

Incorrect Options

Monitoring or logging traffic (Options A and B) without preventing access does not achieve segmentation.

Virtual LANs (Option C) alone are insufficient unless properly configured to enforce traffic isolation​​.

Software Security Framework Overview

PCI SSC’s Software Security Framework (SSF) encompasses Secure Software Standard and Secure Software Lifecycle (Secure SLC) Standard.

Software developed under the Secure SLC Standard adheres to security-by-design principles and can leverage the SSF during PCI DSS assessments​​.

Applicability

The framework is primarily for software developed by entities or third parties adhering to PCI SSC standards.

It does not apply to legacy payment software listed under PA-DSS unless migrated to SSF​​.

Incorrect Options

Option A: Not all payment software qualifies; it must align with SSF requirements.

Option B: PCI PTS devices are subject to different security requirements.

Option C: PA-DSS-listed software does not automatically meet SSF standards without reassessment.

Scope of Change-Detection Mechanisms

PCI DSS v4.0 requires the implementation of a change-detection mechanism (e.g., file-integrity monitoring) to monitor unauthorized changes to critical files.

Critical files include system configuration and parameter files, application executable files, and scripts used in administrative functions​​.

Intent of Monitoring System Files

These files often control security settings and operational parameters of systems within the Cardholder Data Environment (CDE). Unauthorized changes could compromise system security.

Exclusions

Documents like application vendor manuals and security policies do not qualify as files requiring integrity monitoring since they do not directly impact the security posture or operational functions of systems in the CDE.