The Security/changepassword URL action in SilverStripe 2.3.x before 2.3.10 and 2.4.x before 2.4.4 passes a token as a GET parameter while changing a password through email, which allows remote attackers to obtain sensitive data and hijack the session via the HTTP referer logs on a server, aka "HTTP referer leakage."
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.