includes/specials/SpecialChangePassword.php in MediaWiki before 1.19.14 1.20.x and 1.21.x before 1.21.8 and 1.22.x before 1.22.5 does not properly handle a correctly authenticated but unintended login attempt which makes it easier for remote authenticated users to obtain sensitive information by arranging for a victim to login to the attacker's account as demonstrated by tracking the victim's activity related to a \login CSRF\ issue.