As incorporation of RFID (Radio Frequency IDentification) tags in a wide variety of applications increase, there is a need to ensure the security and privacy of the entity to which these tags are attached. Not surprisingly, this is a very active area as attested by the large number of related published research literature. Recently, the journal engineering applications of artificial intelligence published a paper by Chen and Deng (2009) where the authors propose a mutual authentication protocol for RFID. This protocol has fundamental flaws that can be readily taken advantage by a resourceful adversary. We identify and discuss these vulnerabilities and point out the characteristics of this protocol that exposes it to these vulnerabilities.