4 files changed, 33 insertions, 0 deletions
diff --git a/app/models/concerns/blocks_json_serialization.rb b/app/models/concerns/blocks_json_serialization.rb
new file mode 100644
index 00000000000..cb70c22e207
--- /dev/null
+++ b/app/models/concerns/blocks_json_serialization.rb
@@ -0,0 +1,14 @@
+# Overrides `as_json` and `to_json` to raise an exception when called in order
+# to prevent accidentally exposing attributes
+#
+# Not that that would ever happen... but just in case.
+module BlocksJsonSerialization
+  extend ActiveSupport::Concern
+
+  def to_json
+    raise SecurityError,
+      "JSON serialization has been disabled on #{self.class.name}"
+  end
+
+  alias_method :as_json, :to_json
+end
diff --git a/app/models/user.rb b/app/models/user.rb
index 51941f43919..b52f17cd6a8 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -18,6 +18,7 @@ class User < ActiveRecord::Base
   include CreatedAtFilterable
   include IgnorableColumn
   include BulkMemberAccessLoad
+  include BlocksJsonSerialization
 
   DEFAULT_NOTIFICATION_LEVEL = :participating
 
diff --git a/spec/models/concerns/blocks_json_serialization_spec.rb b/spec/models/concerns/blocks_json_serialization_spec.rb
new file mode 100644
index 00000000000..84f8ccc238e
--- /dev/null
+++ b/spec/models/concerns/blocks_json_serialization_spec.rb
@@ -0,0 +1,17 @@
+require 'rails_helper'
+
+describe BlocksJsonSerialization do
+  DummyModel = Class.new do
+    include BlocksJsonSerialization
+  end
+
+  it 'blocks as_json' do
+    expect { DummyModel.new.to_json }
+      .to raise_error(SecurityError, "JSON serialization has been disabled on DummyModel")
+  end
+
+  it 'blocks to_json' do
+    expect { DummyModel.new.to_json }
+      .to raise_error(SecurityError, "JSON serialization has been disabled on DummyModel")
+  end
+end
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index 4687d9dfa00..e58e7588df0 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -12,6 +12,7 @@ describe User do
     it { is_expected.to include_module(Referable) }
     it { is_expected.to include_module(Sortable) }
     it { is_expected.to include_module(TokenAuthenticatable) }
+    it { is_expected.to include_module(BlocksJsonSerialization) }
   end
 
   describe 'delegations' do