Restrict Guest Access to Allowlisted Domains for NIST 800-53 Compliance
Learn how EXT-03 helps you meet NIST 800-53 requirements for Microsoft 365 and Entra ID security.
NIST 800-53 compliance requires implementing specific controls around restrict guest access to allowlisted domains. This page explains how TrueConfig's EXT-03 control helps you meet NIST 800-53 requirements in your Microsoft 365 environment.
How EXT-03 Addresses NIST 800-53 Requirements
NIST 800-53 requires organizations to implement controls around restrict guest access to allowlisted domains. The EXT-03 control provides:
- Guest invitations are restricted to an allowlist of trusted domains
- Cross-tenant access policies block all other external tenants
- External sharing in SharePoint/OneDrive is restricted to allowed domains
These measures directly support NIST 800-53 compliance by ensuring proper external security in your Microsoft 365 environment.
Implementation for Compliance
To satisfy NIST 800-53 requirements with this control:
- **Enable the control** - Use TrueConfig's one-click remediation
- **Document your implementation** - Record how the control was configured
- **Maintain evidence** - TrueConfig automatically logs compliance status
- **Monitor continuously** - Track any deviations from the expected state
Evidence Collection
For NIST 800-53 audits, you'll need to demonstrate:
- Current configuration state
- Historical compliance data
- Remediation actions taken
- Continuous monitoring in place
TrueConfig provides all of this evidence through its audit trail and reporting features.
Why This Control Matters for NIST 800-53
At Level 3, external collaboration is tightly controlled. Only pre-approved partner organizations can access your tenant. This prevents social engineering and limits data exposure to vetted third parties.
Implementing EXT-03 is an important step toward NIST 800-53 compliance. Combined with TrueConfig's continuous monitoring, you can demonstrate ongoing adherence to NIST 800-53 requirements.
Ready to achieve NIST 800-53 compliance?
TrueConfig continuously monitors your Microsoft 365 tenant for compliance with NIST 800-53 requirements, including this control.