# SC-7(5) — Deny by Default — Allow by Exception

- **Control ID:** SC-7(5)
- **Family:** [SC](/md/families/SC.md)
- **Baselines:** moderate, high
- **Enhancement of:** [SC-7](/md/controls/SC-7.md)

## Description

Deny network communications traffic by default and allow network communications traffic by exception \[assignment\].

## Discussion

Denying by default and allowing by exception applies to inbound and outbound network communications traffic. A deny-all, permit-by-exception network communications traffic policy ensures that only those system connections that are essential and approved are allowed. Deny by default, allow by exception also applies to a system that is connected to an external system.

## Implementation guidance

No content available.

## CSF 2.0 subcategories

No content available.

## Related controls

No content available.

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Derived from official NIST publications (NIST SP 800-53 Rev 5 and NIST CSF 2.0). nistcontrols.com is not affiliated with NIST.