In Blogger Classic, admin users who originally created a blog can be removed by other admin users. This behavior allows for a complete and non-reversible hijack of a Blogger Classic blog through CSRF/XSRF/session riding/one-click attacks.
The process is a two shots attacks, meaning that the victim admin user needs to click on two different links while being authenticated. Due to the nature of blogging, in which admins go through the comments posted by visitors, this attack is very feasible. [...]