From 7a01874b75fdd62ab3626490cdf1c65c0ba659d0 Mon Sep 17 00:00:00 2001
From: Aaron Patterson <aaron.patterson@gmail.com>
Date: Mon, 18 Jan 2016 13:51:02 -0800
Subject: [PATCH] Eliminate instance level writers for class accessors

Instance level writers can have an impact on how the Active Model /
Record objects are saved.  Specifically, they can be used to bypass
validations.  This is a problem if mass assignment protection is
disabled and specific attributes are passed to the constructor.

Conflicts:
	activerecord/lib/active_record/scoping/default.rb
	activesupport/lib/active_support/callbacks.rb

CVE-2016-0753
---
 activemodel/lib/active_model/serializers/json.rb | 2 +-
 activemodel/lib/active_model/validations.rb      | 3 ++-
 activerecord/lib/active_record/enum.rb           | 2 +-
 activerecord/lib/active_record/reflection.rb     | 4 ++--
 activesupport/lib/active_support/callbacks.rb    | 2 +-
 5 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/activerecord/lib/active_record/enum.rb b/activerecord/lib/active_record/enum.rb
index fba7747..c99941e 100644
--- a/activerecord/lib/active_record/enum.rb
+++ b/activerecord/lib/active_record/enum.rb
@@ -68,7 +68,7 @@ module ActiveRecord
   # Where conditions on an enum attribute must use the ordinal value of an enum.
   module Enum
     def self.extended(base)
-      base.class_attribute(:defined_enums)
+      base.class_attribute(:defined_enums, instance_writer: false)
       base.defined_enums = {}
     end

diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb
index 824e005..82b0123 100644
--- a/activerecord/lib/active_record/reflection.rb
+++ b/activerecord/lib/active_record/reflection.rb
@@ -4,8 +4,8 @@ module ActiveRecord
     extend ActiveSupport::Concern
 
     included do
-      class_attribute :_reflections
-      class_attribute :aggregate_reflections
+      class_attribute :_reflections, instance_writer: false
+      class_attribute :aggregate_reflections, instance_writer: false
       self._reflections = {}
       self.aggregate_reflections = {}
     end
-- 
2.2.1