From 5aa44e2ffacf85e6efc0e8eb706bc1a3b6492aec Mon Sep 17 00:00:00 2001

From: Andrew White <andyw@pixeltrix.co.uk>

Date: Fri, 27 Nov 2015 13:46:46 +0000

Subject: [PATCH] Don't short-circuit reject_if proc

When updating an associated record via nested attribute hashes the

reject_if proc could be bypassed if the _destroy flag was set in the

attribute hash and allow_destroy was set to false.

The fix is to only short-circuit if the _destroy flag is set and the

option allow_destroy is set to true. It also fixes an issue where

a new record wasn't created if _destroy was set and the option

allow_destroy was set to false.

CVE-2015-7577

---

 activerecord/lib/active_record/nested_attributes.rb | 14 ++++++++++++--

 1 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/activerecord/lib/active_record/nested_attributes.rb b/activerecord/lib/active_record/nested_attributes.rb

index 04b6182..a8ee082 100644

--- a/activerecord/lib/active_record/nested_attributes.rb

+++ b/activerecord/lib/active_record/nested_attributes.rb

@@ -523,7 +523,7 @@ module ActiveRecord

     # has_destroy_flag? or if a <tt>:reject_if</tt> proc exists for this

     # association and evaluates to +true+.

     def reject_new_record?(association_name, attributes)

-      has_destroy_flag?(attributes) || call_reject_if(association_name, attributes)

+      will_be_destroyed?(association_name, attributes) || call_reject_if(association_name, attributes)

     end

     # Determines if a record with the particular +attributes+ should be

@@ -532,7 +532,8 @@ module ActiveRecord

     #

     # Returns false if there is a +destroy_flag+ on the attributes.

     def call_reject_if(association_name, attributes)

-      return false if has_destroy_flag?(attributes)

+      return false if will_be_destroyed?(association_name, attributes)

+

       case callback = self.nested_attributes_options[association_name][:reject_if]

       when Symbol

         method(callback).arity == 0 ? send(callback) : send(callback, attributes)

@@ -541,6 +542,15 @@ module ActiveRecord

       end

     end

+    # Only take into account the destroy flag if <tt>:allow_destroy</tt> is true

+    def will_be_destroyed?(association_name, attributes)

+      allow_destroy?(association_name) && has_destroy_flag?(attributes)

+    end

+

+    def allow_destroy?(association_name)

+      self.nested_attributes_options[association_name][:allow_destroy]

+    end

+

     def raise_nested_attributes_record_not_found!(association_name, record_id)

       raise RecordNotFound, "Couldn't find #{self.class._reflect_on_association(association_name).klass.name} with ID=#{record_id} for #{self.class.name} with ID=#{id}"

     end

-- 

2.4.9 (Apple Git-60)