MyBB, also known as MyBBoard or MyBulletinBoard, is a powerful, efficient, and free forum package, developed using PHP and MySQL.
Input passed via the 'url' parameter in 'member.php' script is not properly verified before being used to redirect users. This can be exploited to redirect a user to an arbitrary website e.g. when a user clicks a specially crafted link to the affected script hosted on a trusted domain.