Restrict Guest Access to Allowlisted Domains for Zero Trust Compliance
Learn how EXT-03 helps you meet Zero Trust requirements for Microsoft 365 and Entra ID security.
Meeting Zero Trust standards for Microsoft 365 involves implementing controls like EXT-03 (Restrict Guest Access to Allowlisted Domains). This guide covers the specific Zero Trust requirements addressed by this control and how to achieve compliance.
How EXT-03 Addresses Zero Trust Requirements
Zero Trust 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 Zero Trust compliance by ensuring proper external security in your Microsoft 365 environment.
Implementation for Compliance
To satisfy Zero Trust 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 Zero Trust 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 Zero Trust
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 Zero Trust compliance. Combined with TrueConfig's continuous monitoring, you can demonstrate ongoing adherence to Zero Trust requirements.
Ready to achieve Zero Trust compliance?
TrueConfig continuously monitors your Microsoft 365 tenant for compliance with Zero Trust requirements, including this control.