EIDFED-010: AD FS Extranet Lockout Settings
- Platform
- Entra ID / M365
- Category
- Entra ID Federation & Hybrid Identity
- Severity
- Medium
- Zero Trust pillar
- Identity (weight 3)
- Golden fixtures
- 2
- Branch coverage
- Observed: fixtures prove the verdicts they exercise
- Provenance
- baseline
What it checks
AD FS extranet lockout protects against brute-force and password spray attacks targeting the AD FS endpoint exposed to the internet. Without proper extranet lockout configuration, attackers can attempt unlimited password guesses against any federated account through the AD FS proxy, potentially compromising accounts with weak or commonly used passwords. The smart lockout feature in AD FS provides protection while minimizing lockout impact on legitimate users.
Recommended value
Extranet smart lockout enabled with appropriate threshold and observation window configured to prevent brute-force attacks
Remediation
Review the AD FS extranet lockout configuration using Get-AdfsProperties in PowerShell on the AD FS server. Enable extranet smart lockout if not already active and configure an appropriate lockout threshold and observation window based on your organization's authentication patterns. Monitor the AD FS security logs for extranet lockout events and adjust thresholds if legitimate users are being locked out or if brute-force attempts are succeeding.
Fixture-proven verdicts
Every verdict below is proven by a golden fixture in the module's gating test suite. This table derives from the last green run; it cannot be edited by hand.
| Scenario | Expected verdict |
|---|---|
| clean | PASS |
| known-bad | WARN |
Framework mappings
- NIST SP 800-53
- AC-7