ATH-01-001: resolve path and check start before loading blueprints

This is even less of an issue since 411ef239f6, since with that commit we only allow files that the listing returns

Signed-off-by: Jens Langhammer <jens@goauthentik.io>

authentik/blueprints/models.py

@@ -82,7 +82,9 @@ class BlueprintInstance(SerializerModel, ManagedModel, CreatedUpdatedModel):
     def retrieve_file(self) -> str:
         """Get blueprint from path"""
         try:
-            full_path = Path(CONFIG.y("blueprints_dir")).joinpath(Path(self.path))
+            full_path = Path(CONFIG.y("blueprints_dir")).joinpath(Path(self.path)).resolve()
+            if not str(full_path).startswith(CONFIG.y("blueprints_dir")):
+                raise BlueprintRetrievalFailed("Invalid blueprint path")
             with full_path.open("r", encoding="utf-8") as _file:
                 return _file.read()
         except (IOError, OSError) as exc:

authentik/blueprints/tests/test_models.py

@@ -1,34 +1,15 @@
 """authentik managed models tests"""
-from typing import Callable, Type
-
-from django.apps import apps
 from django.test import TestCase
 
-from authentik.blueprints.v1.importer import is_model_allowed
-from authentik.lib.models import SerializerModel
+from authentik.blueprints.models import BlueprintInstance, BlueprintRetrievalFailed
+from authentik.lib.generators import generate_id
 
 
 class TestModels(TestCase):
     """Test Models"""
 
-
-def serializer_tester_factory(test_model: Type[SerializerModel]) -> Callable:
-    """Test serializer"""
-
-    def tester(self: TestModels):
-        if test_model._meta.abstract:  # pragma: no cover
-            return
-        model_class = test_model()
-        self.assertTrue(isinstance(model_class, SerializerModel))
-        self.assertIsNotNone(model_class.serializer)
-
-    return tester
-
-
-for app in apps.get_app_configs():
-    if not app.label.startswith("authentik"):
-        continue
-    for model in app.get_models():
-        if not is_model_allowed(model):
-            continue
-        setattr(TestModels, f"test_{app.label}_{model.__name__}", serializer_tester_factory(model))
+    def test_retrieve_file(self):
+        """Test retrieve_file"""
+        instance = BlueprintInstance.objects.create(name=generate_id(), path="../etc/hosts")
+        with self.assertRaises(BlueprintRetrievalFailed):
+            instance.retrieve()

authentik/blueprints/tests/test_serializer_models.py

@@ -0,0 +1,34 @@
+"""authentik managed models tests"""
+from typing import Callable, Type
+
+from django.apps import apps
+from django.test import TestCase
+
+from authentik.blueprints.v1.importer import is_model_allowed
+from authentik.lib.models import SerializerModel
+
+
+class TestModels(TestCase):
+    """Test Models"""
+
+
+def serializer_tester_factory(test_model: Type[SerializerModel]) -> Callable:
+    """Test serializer"""
+
+    def tester(self: TestModels):
+        if test_model._meta.abstract:  # pragma: no cover
+            return
+        model_class = test_model()
+        self.assertTrue(isinstance(model_class, SerializerModel))
+        self.assertIsNotNone(model_class.serializer)
+
+    return tester
+
+
+for app in apps.get_app_configs():
+    if not app.label.startswith("authentik"):
+        continue
+    for model in app.get_models():
+        if not is_model_allowed(model):
+            continue
+        setattr(TestModels, f"test_{app.label}_{model.__name__}", serializer_tester_factory(model))