SilverStripe 2.3.x before 2.3.10 and 2.4.x before 2.4.4 allows remote attackers to bypass the cross-site request forgery (CSRF) protection mechanism and hijack the authentication of administrators via vectors related to "form action requests" using a controller.
Member_ProfileForm in security/Member.php in SilverStripe 2.3.x before 2.3.7 allows remote attackers to hijack user accounts by saving data using the email address (ID) of another user.
In SilverStripe through 4.6.0-rc1, a FormField with square brackets in the field name skips validation.