MT.1033: Users should be blocked from using legacy authentication.
| ID | MT.1033 |
| Severity | High |
| Suite | Mito |
| Product | Entra ID |
| Feature | Conditional Access |
| Security area | Authentication |
| Resource type | User |
| User impact of fixing | Medium |
| Effort to fix | Medium |
| Framework controls | nist-800-53-r5:CM-7 Least Functionality |
| MITRE ATT&CK | T1078.004, T1110 |
| Reads from | Microsoft Graph |
| Licence needed | AAD_PREMIUM |
What this checks and how to fix it
Section titled “What this checks and how to fix it”Checks if the Conditional Access Policies for blocking legacy authentication is active and used.
Mito evaluates up to five member users (emergency access accounts excluded) with the Conditional Access What If API and creates one result per user (MT.1033.<n>).
See Block legacy authentication - Microsoft Learn
Remediation action
Section titled “Remediation action”Create a Conditional Access policy that blocks legacy authentication for all users, excluding your emergency access accounts.
Mito check. Author: f-bader. Open-source licences.
Open-source licences. CIS Benchmark material © Center for Internet Security, Inc.; CISA SCuBA baselines are public domain (CC0).
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