Search Results for: exploit writing tutorial
Exploit writing tutorial part 11 : Heap Spraying Demystified
A lot has been said and written already about heap spraying, but most of the existing documentation and whitepapers focus on IE7 or older versions.
Although there are a number of public exploits available that target IE8, the exact technique to do so has not been really documented in detail.
Of course, you can probably derive how it works by looking at those public exploits.
With this tutorial, I’m going to provide you with a full and detailed overview on what heap spraying is, and how to use it on old and newer platforms.
I’ll start with some “ancient” techniques (or classic techniques if you will) that can be used on IE6 and IE7.
We’ll also look at heap spraying for non-browser applications.
Next, we’ll talk about precision heap spraying, which is a requirement to make DEP bypass exploits work on IE8.
I’ll finish this tutorial with sharing some of my own research on getting reliable heap spraying to work on IE9.
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Exploit writing tutorial part 10 : Chaining DEP with ROP – the Rubik’s[TM] Cube
About 3 months after finishing my previous exploit writing related tutorial, I finally found some time and fresh energy to start writing a new article.
In the previous tutorials, I have explained the basics of stack based overflows and how they can lead to arbitrary code execution. I discussed direct RET overflows, SEH based exploits, Unicode and other character restrictions, the use of debugger plugins to speed up exploit development, how to bypass common memory protection mechanisms and how to write your own shellcode.
While the first tutorials were really written to learn the basics about exploit development, starting from scratch (targeting people without any knowledge about exploit development) you have most likely discovered that the more recent tutorials continue to build on those basics and require solid knowledge of asm, creative thinking, and some experience with exploit writing in general.
Today’s tutorial is no different. I will continue to build upon everything we have seen and learned in the previous tutorials. Today I will talk about ROP and how it can be used to bypass DEP (and ASLR)…
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Exploit writing tutorial part 9 : Introduction to Win32 shellcoding
Over the last couple of months, I have written a set of tutorials about building exploits that target the Windows stack. One of the primary goals of anyone writing an exploit is to modify the normal execution flow of the application and trigger the application to run arbitrary code… code that is injected by the […]
Exploit writing tutorial part 8 : Win32 Egg Hunting
Introduction Easter is still far away, so this is probably the right time to talk about ways to hunting for eggs (so you would be prepared when the easter bunny brings you another 0day vulnerability) In the first parts of this exploit writing tutorial series, we have talked about stack based overflows and how they […]
Exploit writing tutorial part 7 : Unicode – from 0x00410041 to calc
Finally … after spending a couple of weeks working on unicode and unicode exploits, I’m glad and happy to be able to release this next article in my basic exploit writing series : writing exploits for stack based unicode buffer overflows (wow – that’s a mouthful). You may (or may not) have encountered a situation […]
Exploit writing tutorial part 6 : Bypassing Stack Cookies, SafeSeh, SEHOP, HW DEP and ASLR
Introduction In all previous tutorials in this Exploit writing tutorial series, we have looked at building exploits that would work on Windows XP / 2003 server. The success of all of these exploits (whether they are based on direct ret overwrite or exception handler structure overwrites) are based on the fact that a reliable return […]
Exploit writing tutorial part 5 : How debugger modules & plugins can speed up basic exploit development
In the first parts of this exploit writing tutorial, I have mainly used Windbg as a tool to watch registers and stack contents while evaluating crashes and building exploits. Today, I will discuss some other debuggers and debugger plugins that will help you speed up this process. A typical exploit writing toolkit arsenal should at […]
Exploit writing tutorial part 4 : From Exploit to Metasploit – The basics
In the first parts of the exploit writing tutorial, I have discussed some common vulnerabilities that can lead to 2 types of exploits : stack based buffer overflows (with direct EIP overwrite), and stack based buffer overflows that take advantage of SEH chains. In my examples, I have used perl to demonstrate how to build […]
Exploit writing tutorial part 3b : SEH Based Exploits – just another example
In the previous tutorial post, I have explained the basics of SEH based exploits. I have mentioned that in the most simple case of an SEH based exploit, the payload is structured like this : [Junk][next SEH][SEH][Shellcode] I have indicated that SEH needs to be overwritten by a pointer to “pop pop ret” and that […]
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