← PCI DSS 4.0.1 · Req 1 — Network security controls

1.4 — Controls between trusted and untrusted networks

high network-security

Requirement

Network connections between trusted and untrusted networks (including the internet) are controlled: a DMZ or equivalent limits inbound traffic to authorised system components, anti-spoofing is in place, and system components storing cardholder data are not directly reachable from untrusted networks.

What the engine looks for

Every group below must be satisfied — by an affirmative statement, not a plan, a hedge or a denial — for the control to count as covered. A term ending in … matches any word it begins. Supporting terms do not change the verdict — they raise confidence and distinguish a policy that names a mechanism from one that gestures at a category.

Required element 1 — any one of

untrusted networkuntrusted networksinternetpublic networkdmzpublic-facing

Required element 2 — any one of

firewallrestrictednot directly accessiblenot accessibledmzanti-spoofingblockedonly authorisedonly authorized

Supporting terms — specificity signals

1.4.11.4.21.4.4private ipnatwaf

Contradiction markers

Finding any of these outranks coverage — a policy that admits the gap is worse than silence.

database is publicly accessible exposed to the internet

Equivalent controls elsewhere

Matched on shared topics. Satisfying this control usually moves these too.

Framework	Control	Title	Shared topics
ISO 27001	A.8.21	Security of network services	network-security
SOC 2	CC6.6	Boundary protection	network-security
ISO 27001	A.8.22	Segregation of networks	network-security
NIST CSF 2.0	PR.DS-02	Confidentiality, integrity and availability of data in transit	network-security
NIST CSF 2.0	PR.IR-01	Networks and environments are protected from unauthorised logical access	network-security
NIST CSF 2.0	DE.CM-01	Networks and network services are monitored	network-security