Buffer Overflow Primer Part 5 (Shellcode For Execve)
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Description: Welcome to Part 5 of the Buffer Overflow Primer. If you have not already done so, please start this series by viewing Part 1. The Buffer Overflow Primer requires that you know at least some basic Assembly Language. I have created a series of Assembly Language video tutorials for Hackers here, for those not familiar with the language.
In this video we will learn how to convert the shellcode created in the previous video to a more usable format. It is important to note that the shellcode in the previous video cannot be used as-is becuase it contains NULLs and hardcoded addresses. Thus we need to convert it into something which can be injected into a buffer - i.e. we need to remove the NULLs and setup relative addressing. This video will show how we can replace the NULLs in the shellcode with instructions which results in non-NULL shellcode. Also, we discuss in detail how we can setup relative addressing within the shellcode and modify it at runtime to make it work. This is probably the most important video in the series, if one wants to understand the shellcode generation process completely.
Please download ExecveShellCode.s and ShellCode.c before you view this video.
This video is part of the following groups:
1. Buffer Overflow Exploitation Megaprimer for Linux ( 9 videos)
Comments (18)
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xplt on Fri 25 Feb 2011 Man you're awsome! |
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Vivek-Ramachandran on Sat 26 Feb 2011 Hehe :) Enjoy the series and let me know if you have any feedback. |
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xplt on Sat 26 Feb 2011 You can be sure that I'm having a lot of knowledge about this. I'm studying exploit some times ago, like 1 and half year, and I'm graduating on Computer Cience, and my conclusion paper will be on exploit! :D |
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Vivek-Ramachandran on Sat 26 Feb 2011 @xplt welcome! :) Pass a link on to your friends in class :) |
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xplt on Sun 27 Feb 2011 I've already done this! ;D |
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gnalsa on Sun 17 Apr 2011 I really enjoyed the way you used your slides to step through the program. |
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Col_Loki on Sat 30 Apr 2011 Bloody amazing! Really enjoying this. Again fantastic video. |
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neo_panky on Sat 14 May 2011 Hi Vivek, I m following ur vedios. They are awesome. I am trying practically everything you are teaching. It is wonderful experience. |
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JohnM on Tue 14 Jun 2011 Thanks much for this series, it all makes clear sense, and shows that this is all not so hard as one might think! |
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3ntropy on Sat 18 Jun 2011 Thank you man for all the tutorials and hard work you put into this, this is really helping me a lot in my studies, I just wanted to ask you if you are planning anything interesting about the VPN technology, and I really did enjoy your Caffee Latte vuln. and you defcon speech, you are great, I hope I will contribute to the community one day. Thank you. |
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bsmartt on Sun 26 Jun 2011 thanks, this series is addicting. |
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lardycake on Fri 15 Jul 2011 So clever...so awesome. |
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albahala on Thu 29 Sep 2011 Hi Vivek, |
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ringneckparrot on Sun 30 Oct 2011 @albahal and @neo_panky , you WILL get the error message "Segmentation fault", BUT if you try it out without executing it and continue to the objdump command, you will see that it will work as expected spawning you a bash shell |
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LordNoteworthy on Mon 05 Dec 2011 Hey vivek, keep posting, ur videos are so helpful ! |
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dikien on Sun 25 Dec 2011 I love this series!! always great!! |
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hacknix on Thu 26 Jan 2012 I need someone who is capable of hacking* websites & accessing their email database |
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dragosh on Mon 06 Feb 2012 @neo_panky & @albahala |