Parse Server before 8.6.99 and 9.0.0 before 9.10.3-alpha.2 evaluates checks against the target account during a user update before authorizing the caller, and reflects their outcome in the response. An unauthorized caller, with or without a session, can confirm guessed usernames or emails and, when passwordPolicy.maxPasswordHistory or doNotAllowUsername is set, guessed current or previous passwords, bypassing account lockout.
Incorrect Authorization The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.