This vulnerability impacts applications using the omniauth-apple strategy of OmniAuth and using the
info.email field of OmniAuth's Auth Hash Schema for any kind of identification. The value of this field may be set to any value of the attacker's choice including email addresses of other users.
For example, an application using omniauth-apple with the following code will be impacted:
def omniauth_callback auth_hash = request.env['omniauth.auth'] @authenticated_user = User.find_by(email: auth_hash.info.email) end
Applications not using
info.email for identification but are instead using the
uid field are not impacted in the same manner. Note, these applications may still be negatively affected if the value of
info.email is being used for other purposes.
Applications using affected versions of omniauth-apple are advised to upgrade to omniauth-apple version 1.0.1 or later.
If unable to upgrade to a patched version, monkey patching
OmniAuth::Strategies::Apple#email as follows is advised as a workaround:
module OmniAuth module Strategies class Apple def email id_info['email'] end end end end