Uninformed: Informative Information for the Uninformed

Vol 2» 2005.Sept


Bypassing Windows Hardware-enforced DEP
skape & Skywing
This paper describes a technique that can be used to bypass Windows hardware-enforced Data Execution Prevention (DEP) on default installations of Windows XP Service Pack 2 and Windows 2003 Server Service Pack 1. This technique makes it possible to execute code from regions that are typically non-executable when hardware support is present, such as thread stacks and process heaps. While other techniques have been used to accomplish similar feats, such as returning into NtProtectVirtualMemory, this approach requires no direct reprotecting of memory regions, no copying of arbitrary code to other locations, and does not have issues with NULL bytes. The result is a feasible approach that can be used to easily bypass the enhancements offered by hardware-enforced DEP on Windows in a way that requires very minimal modifications to existing exploits.
pdf | html | txt