feat(m365): add entra_conditional_access_policy_unknown_device_blocked security check

Add new security check entra_conditional_access_policy_unknown_device_blocked for m365 provider.
Includes check implementation, metadata, and unit tests.

prowler/CHANGELOG.md

@@ -39,6 +39,7 @@ All notable changes to the **Prowler SDK** are documented in this file.
 - OpenStack compute service with 7 security checks [(#9944)](https://github.com/prowler-cloud/prowler/pull/9944)
 - OpenStack image service with 6 security checks [(#10096)](https://github.com/prowler-cloud/prowler/pull/10096)
 - IaC `--provider-uid` flag to specify the provider UID for the IaC provider [(#10233)](https://github.com/prowler-cloud/prowler/pull/10233)
+- `entra_conditional_access_policy_unknown_device_blocked` check for M365 provider [(#10235)](https://github.com/prowler-cloud/prowler/pull/10235)
 
 ### 🔄 Changed
 

prowler/compliance/m365/iso27001_2022_m365.json

@@ -242,6 +242,7 @@
         "entra_admin_users_sign_in_frequency_enabled",
         "entra_default_app_management_policy_enabled",
         "entra_all_apps_conditional_access_coverage",
+        "entra_conditional_access_policy_unknown_device_blocked",
         "entra_legacy_authentication_blocked",
         "entra_managed_device_required_for_authentication",
         "entra_seamless_sso_disabled",
@@ -616,6 +617,7 @@
         "defenderxdr_endpoint_privileged_user_exposed_credentials",
         "entra_admin_users_phishing_resistant_mfa_enabled",
         "entra_conditional_access_policy_app_enforced_restrictions",
+        "entra_conditional_access_policy_unknown_device_blocked",
         "entra_managed_device_required_for_authentication",
         "entra_managed_device_required_for_mfa_registration",
         "entra_users_mfa_capable",
@@ -670,6 +672,7 @@
       "Checks": [
         "entra_admin_portals_access_restriction",
         "entra_conditional_access_policy_app_enforced_restrictions",
+        "entra_conditional_access_policy_unknown_device_blocked",
         "entra_policy_guest_users_access_restrictions",
         "sharepoint_external_sharing_restricted"
       ]
@@ -690,6 +693,7 @@
         "entra_admin_users_mfa_enabled",
         "entra_admin_users_sign_in_frequency_enabled",
         "entra_all_apps_conditional_access_coverage",
+        "entra_conditional_access_policy_unknown_device_blocked",
         "entra_identity_protection_sign_in_risk_enabled",
         "entra_managed_device_required_for_authentication",
         "entra_seamless_sso_disabled",

prowler/compliance/m365/prowler_threatscore_m365.json

@@ -99,6 +99,7 @@
       "Id": "1.1.6",
       "Description": "Ensure a managed device is required for authentication",
       "Checks": [
+        "entra_conditional_access_policy_unknown_device_blocked",
         "entra_managed_device_required_for_authentication"
       ],
       "Attributes": [
@@ -117,6 +118,7 @@
       "Id": "1.1.7",
       "Description": "Ensure a managed device is required for MFA registration",
       "Checks": [
+        "entra_conditional_access_policy_unknown_device_blocked",
         "entra_managed_device_required_for_mfa_registration"
       ],
       "Attributes": [

prowler/providers/m365/services/entra/entra_conditional_access_policy_unknown_device_blocked/entra_conditional_access_policy_unknown_device_blocked.metadata.json

@@ -0,0 +1,39 @@
+{
+  "Provider": "m365",
+  "CheckID": "entra_conditional_access_policy_unknown_device_blocked",
+  "CheckTitle": "Conditional Access policy blocks access from unknown or unsupported device platforms",
+  "CheckType": [],
+  "ServiceName": "entra",
+  "SubServiceName": "",
+  "ResourceIdTemplate": "",
+  "Severity": "medium",
+  "ResourceType": "Conditional Access Policy",
+  "ResourceGroup": "IAM",
+  "Description": "Conditional Access policy that includes **all device platforms** and excludes the five known platforms (`android`, `iOS`, `windows`, `macOS`, `linux`) with a **block** grant control prevents sign-ins from unrecognized or unsupported devices.",
+  "Risk": "Without blocking unknown device platforms, attackers can sign in from **unmanaged or spoofed devices** that bypass compliance and security controls.\n\nThis increases the risk of **unauthorized access** and makes it harder to enforce device-based security policies.",
+  "RelatedUrl": "",
+  "AdditionalURLs": [
+    "https://learn.microsoft.com/en-us/entra/identity/conditional-access/concept-condition-device-platforms",
+    "https://learn.microsoft.com/en-us/entra/identity/conditional-access/howto-policy-unknown-unsupported-device"
+  ],
+  "Remediation": {
+    "Code": {
+      "CLI": "",
+      "NativeIaC": "",
+      "Other": "1. Navigate to the Microsoft Entra admin center https://entra.microsoft.com.\n2. Expand **Protection** > **Conditional Access** and select **Policies**.\n3. Click **New policy**.\n4. Under **Users**, select **All users**.\n5. Under **Target resources**, select **All cloud apps**.\n6. Under **Conditions** > **Device platforms**, set **Include** to **Any device** and **Exclude** the five known platforms: Android, iOS, Windows, macOS, Linux.\n7. Under **Grant**, select **Block access**.\n8. Set the policy to **On** and click **Create**.",
+      "Terraform": ""
+    },
+    "Recommendation": {
+      "Text": "Create a Conditional Access policy that blocks access from unknown device platforms. Include all platforms and exclude the five known ones (`android`, `iOS`, `windows`, `macOS`, `linux`). Pair this with **device compliance** policies for defense in depth, since platform detection relies on user agent strings.",
+      "Url": "https://hub.prowler.com/check/entra_conditional_access_policy_unknown_device_blocked"
+    }
+  },
+  "Categories": [
+    "identity-access"
+  ],
+  "DependsOn": [],
+  "RelatedTo": [
+    "entra_managed_device_required_for_authentication"
+  ],
+  "Notes": "Device platform detection relies on user agent strings, which can be spoofed. This policy should be paired with device compliance policies for stronger security."
+}

prowler/providers/m365/services/entra/entra_conditional_access_policy_unknown_device_blocked/entra_conditional_access_policy_unknown_device_blocked.py

@@ -0,0 +1,79 @@
+from prowler.lib.check.models import Check, CheckReportM365
+from prowler.providers.m365.services.entra.entra_client import entra_client
+from prowler.providers.m365.services.entra.entra_service import (
+    ConditionalAccessGrantControl,
+    ConditionalAccessPolicyState,
+)
+
+KNOWN_PLATFORMS = {"android", "iOS", "windows", "macOS", "linux"}
+
+
+class entra_conditional_access_policy_unknown_device_blocked(Check):
+    """Check if at least one Conditional Access policy blocks unknown device platforms.
+
+    This check verifies that at least one enabled Conditional Access policy
+    blocks access from unknown or unsupported device platforms by including
+    all platforms and excluding the five known ones (android, iOS, windows,
+    macOS, linux) with a block grant control.
+
+    - PASS: An enabled CA policy blocks access from unknown/unsupported device platforms.
+    - FAIL: No CA policy restricts access from unrecognized device platforms.
+    """
+
+    def execute(self) -> list[CheckReportM365]:
+        """Execute the check logic.
+
+        Returns:
+            A list of reports containing the result of the check.
+        """
+        findings = []
+        report = CheckReportM365(
+            metadata=self.metadata(),
+            resource={},
+            resource_name="Conditional Access Policies",
+            resource_id="conditionalAccessPolicies",
+        )
+        report.status = "FAIL"
+        report.status_extended = "No Conditional Access Policy blocks access from unknown or unsupported device platforms."
+
+        for policy in entra_client.conditional_access_policies.values():
+            if policy.state == ConditionalAccessPolicyState.DISABLED:
+                continue
+
+            if not policy.conditions.platform_conditions:
+                continue
+
+            if (
+                "all"
+                not in policy.conditions.platform_conditions.included_platforms
+            ):
+                continue
+
+            if not KNOWN_PLATFORMS.issubset(
+                set(policy.conditions.platform_conditions.excluded_platforms)
+            ):
+                continue
+
+            if (
+                ConditionalAccessGrantControl.BLOCK
+                not in policy.grant_controls.built_in_controls
+            ):
+                continue
+
+            report = CheckReportM365(
+                metadata=self.metadata(),
+                resource=policy,
+                resource_name=policy.display_name,
+                resource_id=policy.id,
+            )
+
+            if policy.state == ConditionalAccessPolicyState.ENABLED_FOR_REPORTING:
+                report.status = "FAIL"
+                report.status_extended = f"Conditional Access Policy '{policy.display_name}' is configured to block unknown device platforms but is only in report-only mode."
+            else:
+                report.status = "PASS"
+                report.status_extended = f"Conditional Access Policy '{policy.display_name}' blocks access from unknown or unsupported device platforms."
+                break
+
+        findings.append(report)
+        return findings

prowler/providers/m365/services/entra/entra_service.py

@@ -256,6 +256,28 @@ class Entra(M365Service):
                                 [],
                             )
                         ],
+                        platform_conditions=(
+                            PlatformConditions(
+                                included_platforms=[
+                                    platform
+                                    for platform in getattr(
+                                        policy.conditions.platforms,
+                                        "include_platforms",
+                                        [],
+                                    )
+                                ],
+                                excluded_platforms=[
+                                    platform
+                                    for platform in getattr(
+                                        policy.conditions.platforms,
+                                        "exclude_platforms",
+                                        [],
+                                    )
+                                ],
+                            )
+                            if getattr(policy.conditions, "platforms", None)
+                            else None
+                        ),
                         user_risk_levels=[
                             RiskLevel(risk_level)
                             for risk_level in getattr(
@@ -798,10 +820,18 @@ class ClientAppType(Enum):
     OTHER_CLIENTS = "other"
 
 
+class PlatformConditions(BaseModel):
+    """Model representing device platform conditions for Conditional Access policies."""
+
+    included_platforms: List[str] = []
+    excluded_platforms: List[str] = []
+
+
 class Conditions(BaseModel):
     application_conditions: Optional[ApplicationsConditions]
     user_conditions: Optional[UsersConditions]
     client_app_types: Optional[List[ClientAppType]]
+    platform_conditions: Optional[PlatformConditions] = None
     user_risk_levels: List[RiskLevel] = []
     sign_in_risk_levels: List[RiskLevel] = []
 

tests/providers/m365/services/entra/entra_conditional_access_policy_unknown_device_blocked/entra_conditional_access_policy_unknown_device_blocked_test.py

@@ -0,0 +1,458 @@
+from unittest import mock
+from uuid import uuid4
+
+from prowler.providers.m365.services.entra.entra_service import (
+    ApplicationsConditions,
+    ConditionalAccessGrantControl,
+    ConditionalAccessPolicyState,
+    Conditions,
+    GrantControlOperator,
+    GrantControls,
+    PersistentBrowser,
+    PlatformConditions,
+    SessionControls,
+    SignInFrequency,
+    SignInFrequencyInterval,
+    UsersConditions,
+)
+from tests.providers.m365.m365_fixtures import DOMAIN, set_mocked_m365_provider
+
+CHECK_MODULE_PATH = "prowler.providers.m365.services.entra.entra_conditional_access_policy_unknown_device_blocked.entra_conditional_access_policy_unknown_device_blocked"
+
+KNOWN_PLATFORMS = ["android", "iOS", "windows", "macOS", "linux"]
+
+
+def _default_session_controls():
+    return SessionControls(
+        persistent_browser=PersistentBrowser(is_enabled=False, mode="always"),
+        sign_in_frequency=SignInFrequency(
+            is_enabled=False,
+            frequency=None,
+            type=None,
+            interval=SignInFrequencyInterval.EVERY_TIME,
+        ),
+    )
+
+
+def _default_conditions(**overrides):
+    defaults = dict(
+        application_conditions=ApplicationsConditions(
+            included_applications=["All"],
+            excluded_applications=[],
+            included_user_actions=[],
+        ),
+        user_conditions=UsersConditions(
+            included_groups=[],
+            excluded_groups=[],
+            included_users=["All"],
+            excluded_users=[],
+            included_roles=[],
+            excluded_roles=[],
+        ),
+        client_app_types=[],
+        platform_conditions=PlatformConditions(
+            included_platforms=["all"],
+            excluded_platforms=KNOWN_PLATFORMS,
+        ),
+        user_risk_levels=[],
+    )
+    defaults.update(overrides)
+    return Conditions(**defaults)
+
+
+def _default_grant_controls(**overrides):
+    defaults = dict(
+        built_in_controls=[ConditionalAccessGrantControl.BLOCK],
+        operator=GrantControlOperator.OR,
+        authentication_strength=None,
+    )
+    defaults.update(overrides)
+    return GrantControls(**defaults)
+
+
+class Test_entra_conditional_access_policy_unknown_device_blocked:
+    def test_no_conditional_access_policies(self):
+        """Test FAIL when there are no Conditional Access policies."""
+        entra_client = mock.MagicMock
+        entra_client.audited_tenant = "audited_tenant"
+        entra_client.audited_domain = DOMAIN
+
+        with (
+            mock.patch(
+                "prowler.providers.common.provider.Provider.get_global_provider",
+                return_value=set_mocked_m365_provider(),
+            ),
+            mock.patch(
+                f"{CHECK_MODULE_PATH}.entra_client",
+                new=entra_client,
+            ),
+        ):
+            from prowler.providers.m365.services.entra.entra_conditional_access_policy_unknown_device_blocked.entra_conditional_access_policy_unknown_device_blocked import (
+                entra_conditional_access_policy_unknown_device_blocked,
+            )
+
+            entra_client.conditional_access_policies = {}
+
+            check = entra_conditional_access_policy_unknown_device_blocked()
+            result = check.execute()
+            assert len(result) == 1
+            assert result[0].status == "FAIL"
+            assert (
+                result[0].status_extended
+                == "No Conditional Access Policy blocks access from unknown or unsupported device platforms."
+            )
+            assert result[0].resource == {}
+            assert result[0].resource_name == "Conditional Access Policies"
+            assert result[0].resource_id == "conditionalAccessPolicies"
+            assert result[0].location == "global"
+
+    def test_policy_disabled(self):
+        """Test FAIL when the only matching policy is disabled."""
+        policy_id = str(uuid4())
+        display_name = "Block Unknown Devices"
+        entra_client = mock.MagicMock
+        entra_client.audited_tenant = "audited_tenant"
+        entra_client.audited_domain = DOMAIN
+
+        with (
+            mock.patch(
+                "prowler.providers.common.provider.Provider.get_global_provider",
+                return_value=set_mocked_m365_provider(),
+            ),
+            mock.patch(
+                f"{CHECK_MODULE_PATH}.entra_client",
+                new=entra_client,
+            ),
+        ):
+            from prowler.providers.m365.services.entra.entra_conditional_access_policy_unknown_device_blocked.entra_conditional_access_policy_unknown_device_blocked import (
+                entra_conditional_access_policy_unknown_device_blocked,
+            )
+            from prowler.providers.m365.services.entra.entra_service import (
+                ConditionalAccessPolicy,
+            )
+
+            entra_client.conditional_access_policies = {
+                policy_id: ConditionalAccessPolicy(
+                    id=policy_id,
+                    display_name=display_name,
+                    conditions=_default_conditions(),
+                    grant_controls=_default_grant_controls(),
+                    session_controls=_default_session_controls(),
+                    state=ConditionalAccessPolicyState.DISABLED,
+                )
+            }
+
+            check = entra_conditional_access_policy_unknown_device_blocked()
+            result = check.execute()
+            assert len(result) == 1
+            assert result[0].status == "FAIL"
+            assert (
+                result[0].status_extended
+                == "No Conditional Access Policy blocks access from unknown or unsupported device platforms."
+            )
+            assert result[0].resource == {}
+            assert result[0].resource_name == "Conditional Access Policies"
+            assert result[0].resource_id == "conditionalAccessPolicies"
+            assert result[0].location == "global"
+
+    def test_policy_enabled_for_reporting_only(self):
+        """Test FAIL when the matching policy is only in report-only mode."""
+        policy_id = str(uuid4())
+        display_name = "Block Unknown Devices"
+        entra_client = mock.MagicMock
+        entra_client.audited_tenant = "audited_tenant"
+        entra_client.audited_domain = DOMAIN
+
+        with (
+            mock.patch(
+                "prowler.providers.common.provider.Provider.get_global_provider",
+                return_value=set_mocked_m365_provider(),
+            ),
+            mock.patch(
+                f"{CHECK_MODULE_PATH}.entra_client",
+                new=entra_client,
+            ),
+        ):
+            from prowler.providers.m365.services.entra.entra_conditional_access_policy_unknown_device_blocked.entra_conditional_access_policy_unknown_device_blocked import (
+                entra_conditional_access_policy_unknown_device_blocked,
+            )
+            from prowler.providers.m365.services.entra.entra_service import (
+                ConditionalAccessPolicy,
+            )
+
+            entra_client.conditional_access_policies = {
+                policy_id: ConditionalAccessPolicy(
+                    id=policy_id,
+                    display_name=display_name,
+                    conditions=_default_conditions(),
+                    grant_controls=_default_grant_controls(),
+                    session_controls=_default_session_controls(),
+                    state=ConditionalAccessPolicyState.ENABLED_FOR_REPORTING,
+                )
+            }
+
+            check = entra_conditional_access_policy_unknown_device_blocked()
+            result = check.execute()
+            assert len(result) == 1
+            assert result[0].status == "FAIL"
+            assert (
+                result[0].status_extended
+                == f"Conditional Access Policy '{display_name}' is configured to block unknown device platforms but is only in report-only mode."
+            )
+            assert (
+                result[0].resource
+                == entra_client.conditional_access_policies[policy_id].dict()
+            )
+            assert result[0].resource_name == display_name
+            assert result[0].resource_id == policy_id
+            assert result[0].location == "global"
+
+    def test_policy_no_platform_conditions(self):
+        """Test FAIL when the policy has no platform conditions."""
+        policy_id = str(uuid4())
+        display_name = "Block Without Platforms"
+        entra_client = mock.MagicMock
+        entra_client.audited_tenant = "audited_tenant"
+        entra_client.audited_domain = DOMAIN
+
+        with (
+            mock.patch(
+                "prowler.providers.common.provider.Provider.get_global_provider",
+                return_value=set_mocked_m365_provider(),
+            ),
+            mock.patch(
+                f"{CHECK_MODULE_PATH}.entra_client",
+                new=entra_client,
+            ),
+        ):
+            from prowler.providers.m365.services.entra.entra_conditional_access_policy_unknown_device_blocked.entra_conditional_access_policy_unknown_device_blocked import (
+                entra_conditional_access_policy_unknown_device_blocked,
+            )
+            from prowler.providers.m365.services.entra.entra_service import (
+                ConditionalAccessPolicy,
+            )
+
+            entra_client.conditional_access_policies = {
+                policy_id: ConditionalAccessPolicy(
+                    id=policy_id,
+                    display_name=display_name,
+                    conditions=_default_conditions(platform_conditions=None),
+                    grant_controls=_default_grant_controls(),
+                    session_controls=_default_session_controls(),
+                    state=ConditionalAccessPolicyState.ENABLED,
+                )
+            }
+
+            check = entra_conditional_access_policy_unknown_device_blocked()
+            result = check.execute()
+            assert len(result) == 1
+            assert result[0].status == "FAIL"
+            assert (
+                result[0].status_extended
+                == "No Conditional Access Policy blocks access from unknown or unsupported device platforms."
+            )
+            assert result[0].resource == {}
+            assert result[0].resource_name == "Conditional Access Policies"
+            assert result[0].resource_id == "conditionalAccessPolicies"
+
+    def test_policy_does_not_include_all_platforms(self):
+        """Test FAIL when the policy does not include all platforms."""
+        policy_id = str(uuid4())
+        display_name = "Partial Platform Block"
+        entra_client = mock.MagicMock
+        entra_client.audited_tenant = "audited_tenant"
+        entra_client.audited_domain = DOMAIN
+
+        with (
+            mock.patch(
+                "prowler.providers.common.provider.Provider.get_global_provider",
+                return_value=set_mocked_m365_provider(),
+            ),
+            mock.patch(
+                f"{CHECK_MODULE_PATH}.entra_client",
+                new=entra_client,
+            ),
+        ):
+            from prowler.providers.m365.services.entra.entra_conditional_access_policy_unknown_device_blocked.entra_conditional_access_policy_unknown_device_blocked import (
+                entra_conditional_access_policy_unknown_device_blocked,
+            )
+            from prowler.providers.m365.services.entra.entra_service import (
+                ConditionalAccessPolicy,
+            )
+
+            entra_client.conditional_access_policies = {
+                policy_id: ConditionalAccessPolicy(
+                    id=policy_id,
+                    display_name=display_name,
+                    conditions=_default_conditions(
+                        platform_conditions=PlatformConditions(
+                            included_platforms=["android", "iOS"],
+                            excluded_platforms=[],
+                        )
+                    ),
+                    grant_controls=_default_grant_controls(),
+                    session_controls=_default_session_controls(),
+                    state=ConditionalAccessPolicyState.ENABLED,
+                )
+            }
+
+            check = entra_conditional_access_policy_unknown_device_blocked()
+            result = check.execute()
+            assert len(result) == 1
+            assert result[0].status == "FAIL"
+            assert (
+                result[0].status_extended
+                == "No Conditional Access Policy blocks access from unknown or unsupported device platforms."
+            )
+            assert result[0].resource == {}
+
+    def test_policy_missing_excluded_platforms(self):
+        """Test FAIL when the policy does not exclude all five known platforms."""
+        policy_id = str(uuid4())
+        display_name = "Incomplete Exclusions"
+        entra_client = mock.MagicMock
+        entra_client.audited_tenant = "audited_tenant"
+        entra_client.audited_domain = DOMAIN
+
+        with (
+            mock.patch(
+                "prowler.providers.common.provider.Provider.get_global_provider",
+                return_value=set_mocked_m365_provider(),
+            ),
+            mock.patch(
+                f"{CHECK_MODULE_PATH}.entra_client",
+                new=entra_client,
+            ),
+        ):
+            from prowler.providers.m365.services.entra.entra_conditional_access_policy_unknown_device_blocked.entra_conditional_access_policy_unknown_device_blocked import (
+                entra_conditional_access_policy_unknown_device_blocked,
+            )
+            from prowler.providers.m365.services.entra.entra_service import (
+                ConditionalAccessPolicy,
+            )
+
+            entra_client.conditional_access_policies = {
+                policy_id: ConditionalAccessPolicy(
+                    id=policy_id,
+                    display_name=display_name,
+                    conditions=_default_conditions(
+                        platform_conditions=PlatformConditions(
+                            included_platforms=["all"],
+                            excluded_platforms=["android", "iOS", "windows"],
+                        )
+                    ),
+                    grant_controls=_default_grant_controls(),
+                    session_controls=_default_session_controls(),
+                    state=ConditionalAccessPolicyState.ENABLED,
+                )
+            }
+
+            check = entra_conditional_access_policy_unknown_device_blocked()
+            result = check.execute()
+            assert len(result) == 1
+            assert result[0].status == "FAIL"
+            assert (
+                result[0].status_extended
+                == "No Conditional Access Policy blocks access from unknown or unsupported device platforms."
+            )
+            assert result[0].resource == {}
+
+    def test_policy_no_block_grant_control(self):
+        """Test FAIL when the policy does not use block as grant control."""
+        policy_id = str(uuid4())
+        display_name = "MFA Instead of Block"
+        entra_client = mock.MagicMock
+        entra_client.audited_tenant = "audited_tenant"
+        entra_client.audited_domain = DOMAIN
+
+        with (
+            mock.patch(
+                "prowler.providers.common.provider.Provider.get_global_provider",
+                return_value=set_mocked_m365_provider(),
+            ),
+            mock.patch(
+                f"{CHECK_MODULE_PATH}.entra_client",
+                new=entra_client,
+            ),
+        ):
+            from prowler.providers.m365.services.entra.entra_conditional_access_policy_unknown_device_blocked.entra_conditional_access_policy_unknown_device_blocked import (
+                entra_conditional_access_policy_unknown_device_blocked,
+            )
+            from prowler.providers.m365.services.entra.entra_service import (
+                ConditionalAccessPolicy,
+            )
+
+            entra_client.conditional_access_policies = {
+                policy_id: ConditionalAccessPolicy(
+                    id=policy_id,
+                    display_name=display_name,
+                    conditions=_default_conditions(),
+                    grant_controls=_default_grant_controls(
+                        built_in_controls=[ConditionalAccessGrantControl.MFA]
+                    ),
+                    session_controls=_default_session_controls(),
+                    state=ConditionalAccessPolicyState.ENABLED,
+                )
+            }
+
+            check = entra_conditional_access_policy_unknown_device_blocked()
+            result = check.execute()
+            assert len(result) == 1
+            assert result[0].status == "FAIL"
+            assert (
+                result[0].status_extended
+                == "No Conditional Access Policy blocks access from unknown or unsupported device platforms."
+            )
+            assert result[0].resource == {}
+
+    def test_policy_enabled_and_compliant(self):
+        """Test PASS when an enabled policy blocks unknown device platforms."""
+        policy_id = str(uuid4())
+        display_name = "Block Unknown Devices"
+        entra_client = mock.MagicMock
+        entra_client.audited_tenant = "audited_tenant"
+        entra_client.audited_domain = DOMAIN
+
+        with (
+            mock.patch(
+                "prowler.providers.common.provider.Provider.get_global_provider",
+                return_value=set_mocked_m365_provider(),
+            ),
+            mock.patch(
+                f"{CHECK_MODULE_PATH}.entra_client",
+                new=entra_client,
+            ),
+        ):
+            from prowler.providers.m365.services.entra.entra_conditional_access_policy_unknown_device_blocked.entra_conditional_access_policy_unknown_device_blocked import (
+                entra_conditional_access_policy_unknown_device_blocked,
+            )
+            from prowler.providers.m365.services.entra.entra_service import (
+                ConditionalAccessPolicy,
+            )
+
+            entra_client.conditional_access_policies = {
+                policy_id: ConditionalAccessPolicy(
+                    id=policy_id,
+                    display_name=display_name,
+                    conditions=_default_conditions(),
+                    grant_controls=_default_grant_controls(),
+                    session_controls=_default_session_controls(),
+                    state=ConditionalAccessPolicyState.ENABLED,
+                )
+            }
+
+            check = entra_conditional_access_policy_unknown_device_blocked()
+            result = check.execute()
+            assert len(result) == 1
+            assert result[0].status == "PASS"
+            assert (
+                result[0].status_extended
+                == f"Conditional Access Policy '{display_name}' blocks access from unknown or unsupported device platforms."
+            )
+            assert (
+                result[0].resource
+                == entra_client.conditional_access_policies[policy_id].dict()
+            )
+            assert result[0].resource_name == display_name
+            assert result[0].resource_id == policy_id
+            assert result[0].location == "global"