Reverse Engineering is the process of identifying a software or hardware logic by investigating the software binary code or hardware behavior. Programmable Logic Controllers are one of the most (if not the most) critical embedded devices in the industry. PLCs can control almost all the crucial elements of an industrial process and are considered the ’brain of modern industrial control systems’. With recent advances in Industry 4.0, the concept of PLCs operating in an air gapped network became a myth. Thus, with growing accessability of these devices, vendors which historically did not have to worry about their product security, try to find shortcuts while working on improving the security of their product. In this talk, we will take a look into how some of these shortcuts might affect the vendors product security. We finally talk about few other PLC vendors which have similar functionality but are less critical. We end by taking a look at overall roadblocks on reverse engineering the PLCs to identify security issues or similar special access functionalities.