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SC-7(26) SC · System and Communications Protection

Classified National Security System Connections

LOW MODERATE HIGH
1 Overlay 0 Related Controls
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Requirements NIST SOURCE

Prohibit the direct connection of a classified national security system to an external network without the use of [boundary protection device].

Discussion (NIST Supplemental Guidance)

A direct connection is a dedicated physical or virtual connection between two or more systems. Organizations typically do not have complete control over external networks, including the Internet. Boundary protection devices (e.g., firewalls, gateways, and routers) mediate communications and information flows between classified national security systems and external networks. In addition, approved boundary protection devices (typically managed interface or cross-domain systems) provide information flow enforcement from systems to external networks.

Implementation Guidance

Engineering Interpretation

Original engineering commentary written for this explorer — not NIST source text and not authoritative guidance.

No engineering interpretation has been authored for SC-7(26) yet. This section is architected to receive it — see the Requirements and Assessment sections above for the authoritative NIST source content in the meantime.

Assessment

NIST SP 800-53A REV 5.2.0

Assessment Objectives

  1. the boundary protection device required for a direct connection to an external network is defined;
  2. the direct connection of classified national security system to an external network without the use of a <SC-07(26)_ODP boundary protection device> is prohibited.

Examine

[SELECT FROM: System and communications protection policy; procedures addressing boundary protection; system design documentation; system hardware and software; system architecture; system configuration settings and associated documentation; system audit records; system security plan; other relevant documents or records].

Interview

[SELECT FROM: System/network administrators; organizational personnel with information security responsibilities; system developer; organizational personnel with boundary protection responsibilities].

Test

[SELECT FROM: Mechanisms prohibiting the direct connection of classified national security systems to an external network].

Overlays

Showing the OT/ICS overlay for the parent control SC-7 — see the SC-7(26) entries within each baseline below.

OT/ICS Overlay SP 800-82r3

NIST SP 800-82r3 Appendix F, Table 22. Blank baseline means the control/control enhancement is not selected in that initial OT baseline.

LOW

  • Base control: Included (matches standard baseline)
  • Added: (28) (29)

MODERATE

  • Base control: Included (matches standard baseline)
  • Included: (3) (4) (5) (7) (8)
  • Added: (18) (28) (29)

HIGH

  • Base control: Included (matches standard baseline)
  • Included: (3) (4) (5) (7) (8) (18) (21)
  • Added: (28) (29)

STIGs & CCIs

No STIG checks or CCI mappings are currently loaded for SC-7(26). This section is architected to display, per product: STIG ID, Finding ID, Severity, Title, Description, Check, Fix, CCI, and NIST control mapping — but nothing is populated here until a real DISA STIG/CCI dataset is ingested.

Learn more about STIG/CCI integration →

Evidence

Potential Evidence — Derived

Categorized from the SP 800-53A "Examine"/"Test" artifact list above by keyword — not an authoritative NIST evidence list.

Policy

  • System and communications protection policy
  • system security plan

Configuration

  • system design documentation
  • system architecture
  • system configuration settings and associated documentation

Testing

  • Mechanisms prohibiting the direct connection of classified national security systems to an external network

Other Records

  • procedures addressing boundary protection
  • system hardware and software
  • system audit records
  • other relevant documents or records