Fixes #308

stix2/properties.py

@@ -16,8 +16,8 @@ import stix2
 from .base import _Observable, _STIXBase
 from .core import STIX2_OBJ_MAPS, parse, parse_observable
 from .exceptions import (
-    CustomContentError, DictionaryKeyError, MissingPropertiesError,
-    MutuallyExclusivePropertiesError,
+    CustomContentError, DictionaryKeyError, ExtraPropertiesError,
+    MissingPropertiesError, MutuallyExclusivePropertiesError,
 )
 from .utils import _get_dict, get_class_hierarchy_names, parse_into_datetime
 
@@ -200,7 +200,10 @@ class ListProperty(Property):
                 obj_type = self.contained
 
             if isinstance(valid, collections.Mapping):
-                result.append(obj_type(**valid))
+                try:
+                    result.append(obj_type(**valid))
+                except ExtraPropertiesError:
+                    result.append(obj_type(allow_custom=True, **valid))
             else:
                 result.append(obj_type(valid))
 

stix2/test/v21/test_indicator.py

@@ -205,3 +205,31 @@ def test_invalid_indicator_pattern():
     assert excinfo.value.cls == stix2.v21.Indicator
     assert excinfo.value.prop_name == 'pattern'
     assert 'mismatched input' in excinfo.value.reason
+
+
+def test_indicator_with_custom_embedded_objs():
+    now = dt.datetime(2017, 1, 1, 0, 0, 1, tzinfo=pytz.utc)
+    epoch = dt.datetime(1970, 1, 1, 0, 0, 1, tzinfo=pytz.utc)
+
+    ext_ref = stix2.v21.ExternalReference(
+        source_name="Test",
+        description="Example Custom Ext Ref",
+        random_custom_prop="This is a custom property",
+        allow_custom=True,
+    )
+
+    ind = stix2.v21.Indicator(
+        type="indicator",
+        id=INDICATOR_ID,
+        created=now,
+        modified=now,
+        pattern="[file:hashes.MD5 = 'd41d8cd98f00b204e9800998ecf8427e']",
+        pattern_type="stix",
+        valid_from=epoch,
+        indicator_types=['malicious-activity'],
+        external_references=[ext_ref],
+    )
+
+    assert ind.indicator_types == ['malicious-activity']
+    assert len(ind.external_references) == 1
+    assert ind.external_references[0] == ext_ref