Certificateless aggregate signature allows mapping n signatures on n distinct messages from n distinct users into a single length signature. Recently Deng et al proposed CLAS Scheme which is an improvement of Hou et al scheme and claims that their scheme is secure against type II adversary but unfortunately it is found unsecure by applying the Honest but Curious attack by adversary II. In this we show that Deng et al proposed scheme is insecure against type II adversary.