A two-factor multi-gateway authentication technique was developed by Chen et al. for wireless sensor networks (WSNs). In their article, they introduced a multiple gateway authentication protocol based on a password and smart card. They claimed that their technique is impervious to a variety of assaults, including offline password guessing attempt and insider attack. However, after reviewing their scheme, we found some flaws in it, such as insider attack, offline password guessing attack, etc. In conclusion, we offer several recommendations to enhance the analyzed scheme and address the identified weaknesses.