Update handlers.py

Author: benediktjohannes

Lib/wsgiref/handlers.py

@@ -264,6 +264,8 @@ def _convert_string_type(self, value, title, *, name):
         """Convert/check value type."""
         if type(value) is str:
             regex = (_name_disallowed_re if name else _value_disallowed_re)
+            if regex.search(value):
+                raise ValueError("Control characters not allowed in headers, values and statuses")
             return value
         raise AssertionError(
             "{0} must be of type str (got {1})".format(title, repr(value))