My site will have an extremely insecure subdomain, and a secure root domain. Say http://test.example.com
and http://example.com
, the root domain will have a login cookie. Wikipedia indicates they would not have same origin, hence the login cookie could not be read by the subdomain. However, I am hesitant to believe that seeing as logins on Wikipedia itself carry over regardless of subdomain.
On the same note, I would like to confirm in that scenario, if I were to use a sandboxed iframe displaying the subdomain in my root domain the subdomain would not have access to the login cookie.