From f943e386039e0f28e777e2cf7ec39a7dbe24c040 Mon Sep 17 00:00:00 2001
From: Aaron Patterson <aaron.patterson@gmail.com>
Date: Fri, 4 Jan 2013 12:02:22 -0800
Subject: [PATCH 1/2] * Strip nils from collections on JSON and XML posts.
 [CVE-2013-0155] * dealing with empty hashes. Thanks
 Damien Mathieu

---
 actionpack/lib/action_dispatch/http/request.rb        |   10 ++++------
 .../lib/action_dispatch/middleware/params_parser.rb   |    4 ++--
 2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/actionpack/lib/action_dispatch/http/request.rb b/actionpack/lib/action_dispatch/http/request.rb
index 04b4a21..8767acb 100644
--- a/actionpack/lib/action_dispatch/http/request.rb
+++ b/actionpack/lib/action_dispatch/http/request.rb
@@ -258,18 +258,14 @@ module ActionDispatch
       LOCALHOST.any? { |local_ip| local_ip === remote_addr && local_ip === remote_ip }
     end
 
-    protected
-
     # Remove nils from the params hash
     def deep_munge(hash)
-      keys = hash.keys.find_all { |k| hash[k] == [nil] }
-      keys.each { |k| hash[k] = nil }
-
-      hash.each_value do |v|
+      hash.each do |k, v|
         case v
         when Array
           v.grep(Hash) { |x| deep_munge(x) }
           v.compact!
+          hash[k] = nil if v.empty?
         when Hash
           deep_munge(v)
         end
@@ -278,6 +274,8 @@ module ActionDispatch
       hash
     end
 
+    protected
+
     def parse_query(qs)
       deep_munge(super)
     end
diff --git a/actionpack/lib/action_dispatch/middleware/params_parser.rb b/actionpack/lib/action_dispatch/middleware/params_parser.rb
index d4208ca..aaf9680 100644
--- a/actionpack/lib/action_dispatch/middleware/params_parser.rb
+++ b/actionpack/lib/action_dispatch/middleware/params_parser.rb
@@ -38,13 +38,13 @@ module ActionDispatch
         when Proc
           strategy.call(request.raw_post)
         when :xml_simple, :xml_node
-          data = Hash.from_xml(request.body.read) || {}
+          data = request.deep_munge(Hash.from_xml(request.body.read) || {})
           request.body.rewind if request.body.respond_to?(:rewind)
           data.with_indifferent_access
         when :yaml
           YAML.load(request.raw_post)
         when :json
-          data = ActiveSupport::JSON.decode(request.body)
+          data = request.deep_munge ActiveSupport::JSON.decode(request.body)
           request.body.rewind if request.body.respond_to?(:rewind)
           data = {:_json => data} unless data.is_a?(Hash)
           data.with_indifferent_access
-- 
1.7.10.2 (Apple Git-33)