Merge commit from fork

Author: d-maurer

CHANGES.rst

@@ -10,6 +10,8 @@ Changes
   it as ``getattr`` implementation. Such use should now follow the same policy
   and give the same level of protection as direct attribute access in an
   environment based on ``RestrictedPython``'s ``safe_builtints``.
+- Prevent information leakage via ``AttributeError.obj``
+  and the ``string`` module.
 
 
 7.2 (2024-08-02)

src/RestrictedPython/Utilities.py

@@ -29,7 +29,11 @@ def __getattr__(self, attr):
         if attr in self.__excludes:
             raise NotImplementedError(
                 f"{self.__mod.__name__}.{attr} is not safe")
-        return getattr(self.__mod, attr)
+        try:
+            return getattr(self.__mod, attr)
+        except AttributeError as e:
+            e.obj = self
+            raise
 
 
 utility_builtins['string'] = _AttributeDelegator(string, "Formatter")

tests/builtins/test_utilities.py

@@ -7,8 +7,17 @@ def test_string_in_utility_builtins():
     from RestrictedPython.Utilities import utility_builtins
 
     # we no longer provide access to ``string`` itself, only to
-    # a restricted view of it
-    assert utility_builtins['string'].__name__ == string.__name__
+    # a restricted view of it (``rstring``)
+    rstring = utility_builtins['string']
+    assert rstring.__name__ == string.__name__
+
+    # ensure it does not provide access to ``string`` via
+    # ``AttributeError.obj``
+    try:
+        rstring.unexisting_attribute
+    except AttributeError as e:
+        assert e.obj is rstring
+        
 
 
 def test_math_in_utility_builtins():