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NET-18.1: Route Internal Traffic to Proxy Servers

NET 9 — Critical Protect

Mechanisms exist to route internal communications traffic to external networks through organization-approved proxy servers at managed interfaces.

Control Question: Does the organization route internal communications traffic to external networks through organization-approved proxy servers at managed interfaces?

General (14)
Framework Mapping Values
CIS CSC 8.1 13.10
CIS CSC 8.1 IG3 13.10
GovRAMP Moderate SC-07(08)
GovRAMP High SC-07(08)
MPA Content Security Program 5.1 TS-2.8
NIST 800-53 R4 SC-7(8)
NIST 800-53 R4 (high) SC-7(8)
NIST 800-53 R5 (source) SC-7(8)
NIST 800-53B R5 (moderate) (source) SC-7(8)
NIST 800-53B R5 (high) (source) SC-7(8)
NIST 800-82 R3 MODERATE OT Overlay SC-7(8)
NIST 800-82 R3 HIGH OT Overlay SC-7(8)
SWIFT CSF 2023 1.4
SCF CORE Mergers, Acquisitions & Divestitures (MA&D) NET-18.1
US (13)
EMEA (3)
APAC (2)
Framework Mapping Values
APAC Australia ISM June 2024 ISM-0260 ISM-0570 ISM-1237
APAC New Zealand NZISM 3.6 14.3.6.C.01 14.3.6.C.02 14.3.6.C.03

Capability Maturity Model

Level 0 — Not Performed

There is no evidence of a capability to route internal communications traffic to external networks through organization-approved proxy servers at managed interfaces.

Level 1 — Performed Informally

Network Security (NET) efforts are ad hoc and inconsistent. CMM Level 1 control maturity would reasonably expect all, or at least most, the following criteria to exist:

  • IT personnel use an informal process to design, build and maintain secure networks for test, development, staging and production environments, including the implementation of appropriate cybersecurity and data protection controls.
  • Administrative processes are used to configure boundary devices (e.g., firewalls, routers, etc.) to deny network traffic by default and allow network traffic by exception (e.g., deny all, permit by exception).
  • Network monitoring is primarily reactive in nature.
Level 2 — Planned & Tracked

Network Security (NET) efforts are requirements-driven and governed at a local/regional level, but are not consistent across the organization. CMM Level 2 control maturity would reasonably expect all, or at least most, the following criteria to exist:

  • Network security management is decentralized (e.g., a localized/regionalized function) and uses non-standardized methods to implement secure, resilient and compliant practices.
  • IT/cybersecurity personnel identify cybersecurity and data protection controls that are appropriate to address applicable statutory, regulatory and contractual requirements for network security management.
  • IT personnel define secure networking practices to protect the confidentiality, integrity, availability and safety of the organization's technology assets, data and network(s).
  • Administrative processes and technologies focus on protecting High Value Assets (HVAs), including environments where sensitive/regulated data is stored, transmitted and processed.
  • Administrative processes are used to configure boundary devices (e.g., firewalls, routers, etc.) to deny network traffic by default and allow network traffic by exception (e.g., deny all, permit by exception).
  • Network segmentation exists to implement separate network addresses (e.g., different subnets) to connect systems in different security domains (e.g., sensitive/regulated data environments).
  • Technologies are configured to force Internet-bound network traffic through a proxy device for URL content filtering to limit a user's ability to connect to prohibited content.
Level 3 — Well Defined

Network Security (NET) efforts are standardized across the organization and centrally managed, where technically feasible, to ensure consistency. CMM Level 3 control maturity would reasonably expect all, or at least most, the following criteria to exist:

  • A Technology Infrastructure team, or similar function, defines centrally-managed network security controls for implementation across the enterprise.
  • Secure engineering principles are used to design and implement network security controls (e.g., industry-recognized secure practices) to enforce the concepts of least privilege and least functionality at the network level.
  • IT/cybersecurity architects work with the Technology Infrastructure team to implement a “layered defense” network architecture that provides a defense-in-depth approach for redundancy and risk reduction for network-based security controls, including wired and wireless networking.
  • Administrative processes and technologies configure boundary devices (e.g., firewalls, routers, etc.) to deny network traffic by default and allow network traffic by exception (e.g., deny all, permit by exception).
  • Technologies automate the Access Control Lists (ACLs) and similar rulesets review process to identify security issues and/ or misconfigurations.
  • Network segmentation exists to implement separate network addresses (e.g., different subnets) to connect systems in different security domains (e.g., sensitive/regulated data environments).
Level 4 — Quantitatively Controlled

See C|P-CMM3. There are no defined C|P-CMM4 criteria, since it is reasonable to assume a quantitatively-controlled process is not necessary to route internal communications traffic to external networks through organization-approved proxy servers at managed interfaces.

Level 5 — Continuously Improving

See C|P-CMM4. There are no defined C|P-CMM5 criteria, since it is reasonable to assume a continuously-improving process is not necessary to route internal communications traffic to external networks through organization-approved proxy servers at managed interfaces.

Assessment Objectives

  1. NET-18.1_A01 internal communications traffic to be routed to external networks is defined.
  2. NET-18.1_A02 external networks to which internal communications traffic is to be routed are defined.
  3. NET-18.1_A03 internal communications traffic is routed to external networks through authenticated proxy servers at managed interfaces.

Evidence Requirements

E-NET-01 Content / DNS Filtering

Documented evidence of the methods that content / DNS filtering is implemented to prevent Internet traffic from prohibited content and/or hostile web sites.

Network Security

Technology Recommendations

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