phpMyFAQ: Path traversal in Client::deleteClientFolder enables arbitrary directory deletion by non-super-admin admins

phpMyFAQ before 4.1.2 contains a path traversal vulnerability in Client::deleteClientFolder that allows admins with INSTANCE_DELETE permission to delete arbitrary directories. Attackers can submit traversal sequences like https://../../../<path> in the client URL parameter to recursively delete directories outside the intended clientFolder scope.