🔐(backend) avoids revealing the inactive status of an application

Authenticate the application secret before checking whether the
application is inactive.

This avoids revealing the inactive status of an application when
an incorrect secret is provided, preventing an authentication
state oracle and client_id enumeration.

CHANGELOG.md

@@ -25,6 +25,7 @@ and this project adheres to
 - 🌐(frontend) improve German translation #1125
 - 🔨(python-env) migrate meet main app to UV #1120
 - ♻️(backend) align Application model field with `is_active` convention #1133
+- 🔐(backend) avoids revealing the inactive status of an application #1135
 
 ### Fixed
 

compose.yml

@@ -58,7 +58,7 @@ services:
       /usr/bin/mc admin config set meet notify_webhook:meet-webhook endpoint='http://app-dev:8000/api/v1.0/recordings/storage-hook/' auth_token='Bearer password' &&
       /usr/bin/mc admin service restart meet --wait --json &&
       sleep 15 &&
-      /usr/bin/mc event add meet/meet-media-storage arn:minio:sqs::meet-webhook:webhook --event put &&
+      /usr/bin/mc event add meet/meet-media-storage arn:minio:sqs::meet-webhook:webhook --event put --prefix "recordings" &&
       exit 0;"
 
   app-dev:

src/backend/core/external_api/viewsets.py

@@ -61,12 +61,12 @@ class ApplicationViewSet(viewsets.ViewSet):
         except models.Application.DoesNotExist as e:
             raise drf_exceptions.AuthenticationFailed("Invalid credentials") from e
 
-        if not application.is_active:
-            raise drf_exceptions.AuthenticationFailed("Application is inactive")
-
         if not check_password(client_secret, application.client_secret):
             raise drf_exceptions.AuthenticationFailed("Invalid credentials")
 
+        if not application.is_active:
+            raise drf_exceptions.AuthenticationFailed("Application is inactive")
+
         email = serializer.validated_data["scope"]
         try:
             validate_email(email)

src/backend/core/tests/test_external_api_token.py

@@ -122,6 +122,28 @@ def test_api_applications_generate_token_inactive_application():
     assert "Application is inactive" in str(response.data)
 
 
+def test_api_applications_generate_token_inactive_application_wrong_secret():
+    """An inactive application with a wrong secret should return 401."""
+    user = UserFactory(email="user@example.com")
+    application = ApplicationFactory(is_active=False)
+
+    client = APIClient()
+    response = client.post(
+        "/external-api/v1.0/application/token/",
+        {
+            "client_id": application.client_id,
+            "client_secret": "wrong-secret",
+            "grant_type": "client_credentials",
+            "scope": user.email,
+        },
+        format="json",
+    )
+
+    assert response.status_code == 401
+    assert "Invalid credentials" in str(response.data)
+    assert "inactive" not in str(response.data).lower()
+
+
 def test_api_applications_generate_token_invalid_email_format():
     """Invalid email format should return 400."""
     application = ApplicationFactory(is_active=True)

src/helm/extra/templates/minio.yaml

@@ -132,7 +132,7 @@ spec:
             /usr/bin/mc admin config set meet notify_webhook:meet-webhook endpoint="https://meet.127.0.0.1.nip.io/api/v1.0/recordings/storage-hook/" auth_token="Bearer password" && \
             /usr/bin/mc admin service restart meet --wait --json && \
             sleep 15 && \
-            /usr/bin/mc event add meet/meet-media-storage arn:minio:sqs::meet-webhook:webhook --event put && \
+            /usr/bin/mc event add meet/meet-media-storage arn:minio:sqs::meet-webhook:webhook --event put --prefix "recordings" && \
             exit 0
       restartPolicy: Never
   backoffLimit: 1