The objective of Sans signature buffer overflow blocker is to intercept communications between a server and client,analyse the contents for the presence of executable code and prevent the code reaching the server.This system will analyse the incoming of the data,check is it contains any executable code.If the executable code is found, the packet is dropped,otherwise it is allowed to pass through. Given the intelligence of the algorithm, it prevents most of the buffer overflow attacks. The system can handle the packet analysis in a transparent manner, thus making it suitable for deployment at Firewall/Application Gateway level.