Writable XOR executable (W(○)X) and address space layout randomisation (ASLR) have elevated the understanding necessary to perpetrate buffer overflow exploits[1].However,they have not proved to be a panacea[1 -3],and so other mechanisms,such as stack guards and prelinking,have been introduced.In this paper,we show that host-based protection still does not offer a complete solution.To demonstrate the protection inadequacies,we perform an over the network brute force return-to-libc attack against a preforking concurrent server to gain remote access to a shell.The attack defeats host protection including W(○)X and ASLR.We then demonstrate that deploying a network intrusion detection systems (NIDS) with appropriate signatures can detect this attack efficiently.