activerecord/lib/active_record/nested_attributes.rb in Active Record in Ruby on Rails 3.1.x and 3.2.x before 3.2.22.1, 4.0.x and 4.1.x before 4.1.14.1, 4.2.x before 4.2.5.1, and 5.x before 5.0.0.beta1.1 does not properly implement a certain destroy option, which allows remote attackers to bypass intended change restrictions by leveraging use of the nested attributes feature.

The http_basic_authenticate_with method in actionpack/lib/action_controller/metal/http_authentication.rb in the Basic Authentication implementation in Action Controller in Ruby on Rails before 3.2.22.1, 4.0.x and 4.1.x before 4.1.14.1, 4.2.x before 4.2.5.1, and 5.x before 5.0.0.beta1.1 does not use a constant-time algorithm for verifying credentials, which makes it easier for remote attackers to bypass authentication by measuring timing differences.