Fix SQL injection via nested hashes in conditions

activerecord/lib/active_record/base.rb

@@ -2333,17 +2333,17 @@ module ActiveRecord #:nodoc:
         # And for value objects on a composed_of relationship:
         #   { :address => Address.new("123 abc st.", "chicago") }
         #     # => "address_street='123 abc st.' and address_city='chicago'"
-        def sanitize_sql_hash_for_conditions(attrs, default_table_name = quoted_table_name)
+        def sanitize_sql_hash_for_conditions(attrs, default_table_name = quoted_table_name, top_level = true)
           attrs = expand_hash_conditions_for_aggregates(attrs)
 
           conditions = attrs.map do |attr, value|
             table_name = default_table_name
 
-            unless value.is_a?(Hash)
+            if not value.is_a?(Hash)
               attr = attr.to_s
 
               # Extract table name from qualified attribute names.
-              if attr.include?('.')
+              if attr.include?('.') and top_level
                 attr_table_name, attr = attr.split('.', 2)
                 attr_table_name = connection.quote_table_name(attr_table_name)
               else
@@ -2351,8 +2351,10 @@ module ActiveRecord #:nodoc:
               end
 
               attribute_condition("#{attr_table_name}.#{connection.quote_column_name(attr)}", value)
+            elsif top_level
+              sanitize_sql_hash_for_conditions(value, connection.quote_table_name(attr.to_s), false)
             else
-              sanitize_sql_hash_for_conditions(value, connection.quote_table_name(attr.to_s))
+              raise ActiveRecord::StatementInvalid
             end
           end.join(' AND ')
 

activerecord/test/cases/finder_test.rb

@@ -363,6 +363,22 @@ class FinderTest < ActiveRecord::TestCase
     }
   end
 
+  def test_hash_condition_find_with_improper_nested_hashes
+    assert_raise(ActiveRecord::StatementInvalid) {
+      Company.find(:first, :conditions => { :name => { :companies => { :id  => 1 }}})
+    }
+  end
+
+  def test_hash_condition_find_with_dot_in_nested_column_name
+    assert_raise(ActiveRecord::StatementInvalid) {
+      Company.find(:first, :conditions => { :name => { "companies.id" => 1 }})
+    }
+  end
+
+  def test_hash_condition_find_with_dot_in_column_name_okay
+    assert Company.find(:first, :conditions => { "companies.id" => 1 })
+  end
+
   def test_hash_condition_find_with_escaped_characters
     Company.create("name" => "Ain't noth'n like' \#stuff")
     assert Company.find(:first, :conditions => { :name => "Ain't noth'n like' \#stuff" })