WithPCI Logo
WithPCI.com

Requirement 11: Test Security of Systems and Networks Regularly

Overview

Vulnerabilities are being discovered continually by malicious individuals and researchers, and being introduced by new software. System components, processes, and bespoke and custom software should be tested frequently to ensure security controls continue to reflect a changing environment.

Refer to Appendix G for definitions of PCI DSS terms.

Sections

11. Regularly Test Security of Systems and Networks

Maintain ongoing security validation through comprehensive vulnerability management, penetration testing, and monitoring to protect cardholder data environments from emerging threats.

https://WithPCI.com
21
Sub-requirements
46
Test Points
Moderate (3.0)
Implementation Difficulty

Control Types

Documentation
Governance
Technical
Process (13)

Key Risks

Undetected vulnerabilities in network perimeters
Inadequate segmentation allowing lateral movement
Script tampering on payment pages (Magecart attacks)
Delayed detection of intrusion attempts
Ineffective patch management processes

Frequently Asked Questions

What are the critical updates to Requirement 11 in PCI DSS 4.0.1?

PCI DSS 4.0.1 introduces three key changes: 1) Explicit requirement for authenticated internal vulnerability scans (11.3.1.2), 2) Clarified script authorization processes for payment pages (11.6.1), and 3) Mandated quarterly segmentation validation for service providers. The update emphasizes continuous monitoring rather than periodic checks, requiring integration of vulnerability scanning with patch management workflows.

How often must vulnerability scans be performed?

Organizations must conduct: 1) Quarterly external ASV scans of public-facing systems, 2) Quarterly authenticated internal scans of CDE components, and 3) Ad-hoc scans within 30 days of significant changes (network topology updates, firewall modifications). All critical vulnerabilities (CVSS ≥ 9.0) must be rescanned within 72 hours of remediation.

What are the penetration testing requirements?

Conduct: 1) Annual network-layer tests covering all CDE ingress/egress points, 2) Application-layer tests after major code changes, 3) Segmentation validation tests every 6 months for service providers. Tests must simulate real attacker behavior using OSSTMM or NIST SP 800-115 methodologies. Cloud environments require testing of security groups and IAM policies.

How should payment page script integrity be maintained?

Implement: 1) Automated script allow-listing with cryptographic hashes (SRI), 2) Real-time DOM monitoring for unauthorized changes, 3) Weekly manual inspections of script behavior. PCI DSS 4.0.1 requires documented business justification for each script and immediate revocation of unauthorized modifications.

What documentation is required for compliance?

Maintain: 1) Quarterly vulnerability scan reports with remediation evidence, 2) Penetration test reports showing exploit attempts and retesting results, 3) Script inventory with version-controlled approval records, 4) Continuous monitoring logs from IDS/IPS systems. PCI DSS 4.0.1 mandates cryptographic signing of all test artifacts.

Common QSA Questions

Show evidence of quarterly ASV scans and remediation?

We maintain cryptographically signed reports from SecurityMetrics ASV scans conducted 03/2025, 06/2025, 09/2025, and 12/2024. Each report shows 0 critical vulnerabilities, with rescan confirmation within SLA for 3 high-risk findings. Cloudflare WAF logs demonstrate blocking of CVE-2025-12345 exploit attempts post-remediation.

Demonstrate payment page script controls under 11.6.1?

Our implementation includes: 1) Subresource Integrity hashes for all 23 third-party scripts, 2) Automated revocation of unauthorized scripts via Akamai Page Integrity Manager, 3) Weekly manual audits using BrowserStack to validate DOM integrity. Last penetration test showed 0 successful script injection attempts.

Provide segmentation validation test results?

We conduct bi-annual tests using Metasploit Pro to validate 45 segmentation controls between CDE and corporate networks. Last test on 01/15/2025 achieved 100% segmentation effectiveness, with detailed packet captures showing no lateral movement possibilities. AWS Security Group rules are reviewed monthly via Scout Suite.

Your perspective on this PCI DSS requirement matters! Share your implementation experiences, challenges, or questions below. Your insights help other organizations improve their compliance journey and build a stronger security community.Comment Policy