What evidence do auditors commonly ask for on 1.3.1 Inbound CDE traffic restricted?

NSC configuration standard stating inbound CDE traffic rules and a default deny; Inbound rulesets on CDE boundary NSCs showing specific allows followed by an explicit or implicit deny; Business justification mapping for each inbound rule into the CDE; Segmentation or port scan results confirming unneeded inbound paths are blocked.

What is the most common gap auditors find on 1.3.1?

Inbound rules allow entire corporate subnets into the CDE rather than specific hosts and ports

PCI DSS v4.0.1 · Req 1: Network Security Controls

`1.3.1` Inbound CDE traffic restricted

Traffic entering the cardholder data environment must be restricted so that (a) only necessary traffic is permitted and (b) everything else is explicitly denied. The guidance recommends evaluating all inbound traffic, wherever it originates, against authorised rules, for example by limiting source and destination addresses and ports. Applicability: no special notes; applies to every assessed entity. Customized approach objective: traffic that is not authorised is unable to get into the CDE.

Source: PCI DSS v4.0.1, 1.3.1. The statement above is our statement of the clause, read from the published text and cited so you can check it against the official text, not the instrument verbatim. Open PCI DSS v4.0.1 in the compliance library.

Version 4.0.1 is the active version; 4.0 has been retired. Appendix A1 applies only to multi-tenant service providers, A2 only to card-present POS POI terminals that still use SSL or early TLS, and A3 only when a payment brand or acquirer requires it. Which requirements apply to you follows your validation type.

artefacts

held by a system

at each review

easy

to go live

Cloud console / configuration management

where the evidence lives

teal = a system already holds it · olive = produced at each review. To go live: easy when half or more of the artefacts are already held by a system, moderate from a quarter to a half, hard below a quarter.

These are the artefacts auditors commonly ask for on this requirement, our guidance rather than text from the standard. Your assessor decides what is sufficient in your context, and asks for samples across the period when a report covers one.

system holds itEvidence a system already holds

Inbound rulesets on CDE boundary NSCs showing specific allows followed by an explicit or implicit deny · Cloud console / configuration management
Segmentation or port scan results confirming unneeded inbound paths are blocked · Vulnerability scanner / patch tooling

periodic reviewEvidence produced at each review

none for this control

governing documentDocuments that govern the control

NSC configuration standard stating inbound CDE traffic rules and a default deny · Policy repository / GRC workspace
Business justification mapping for each inbound rule into the CDE · Policy repository / GRC workspace

First move

Automate the pull from your Cloud console / configuration management. Configuration snapshots and change history from the cloud console or IaC repository, diffed against the baseline.

Common gaps auditors find

Inbound rules allow entire corporate subnets into the CDE rather than specific hosts and ports
No explicit deny-all rule, relying on vendor defaults that permit traffic
Cloud CDE security groups allow inbound traffic from any source on management ports

Do this for your whole sheet

Paste the rows you run your controls from and get this mapping for every control at once, with the periodic-review ones flagged and a first move per row. No account for the first run.

Build my evidence sheet

1.2.8 NSC configuration files secured and consistent · 1.3.2 Outbound CDE traffic restricted