login/register_form.php in YourPlace 1.0.2 and earlier does not check that a username already exists when a new account is created, which allows remote attackers to bypass intended access restrictions by registering a new account with the username of a target user.
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.