Showing posts from June, 2018

[Reverse Engineering Primer] Unpacking cramfs firmware file systems

Reverse engineering firmware from the point of view of an attacker involves levering as much as possible what is accessible from the physical board. Of course the classic question this strives to answer is, if someone gets hold of my board what could go wrong? Reverse engineering some devices in the wild often exposes security keys, default passwords and other forms of security failures that can expose an unfair escalation of privilege or perhaps also allow a complete take over of the device right down to boot loader level - all of this sometimes also possibly learned by analyzing the firmware.

I'm going to talk about some of the more basic skill in getting toward exposing the code and other sensitive artifacts used by the device. Before you can find remote code execs and admin auth by pass vulns you need to get to grips with firmware image formats and embedded file systems.

Setting up the environment 
Before getting super in depth and writing our own file format parsers, machine …

Windows Exploit Development : Exploiting Structured Exception Handling and ROP Chaining

Hi folks this post is a continuation of a series I'm doing covering the fundamentals of windows exploit development. In this post I'm going to inch a little closer to arbitrary code execution by showing you how to chain ROP gadgets and one or two stack pivoting tricks.

So here's how this post is going to go:
We we're gonna look at how Structured Exception handling worksWe're gonna break it and show how it breaksThen we're going to make it execute whatever code we wantFigure out how to fix our stack pointerChain some ROP gadgets What you needWindows Virtual Machine Debugger Tools for windowsEasy MPEG to DVD Burner (copy available on exploit-db)ImmunityDBG(optional) python script Reverse Engineering Structured Exception Handling
Structured Exception handling is a mechanism offered to functions in that allow them to customize their responses to hardware and software exceptions. Hardwar…