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Is This How Buffer Overflows Work?

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#1 joejoejoe

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Posted 11 March 2011 - 04:02 PM


Iguess there are similar questions and some data on the web...but I wantto be sure that I grasp the concept correctly, since all onlinetutorials are way too long and focus on exploits, ect. So, the way Isee it a simple buffer overflow will be something like:

//////////////////////////////////////////////////1. You send a string of arguments/input like that: nopinstructions(x90) + shellcode + some text + address of some nopinstruction. 2. If the string is of the correct length it will overridethe return address ebp with the address of some of the nopinstructions. Once it jumps there - it will then skip until reachingthe shellcode....and the rest is history.////////////////////////////////////////////////

is thedescription above something along the line? Plus, as far as Iunderstand there are some protections against buffers ovs., though Idon't undertand them yet. How will firewall catch this?

10x!



#2 OpticHash

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Posted 19 September 2011 - 02:28 PM

Firewalls generally look for the Nop-sled in exploits. Generally this won't matter because everyone uses Metasploit nowadays and you can encode payloads.

First result when googling buffer overflow
http://en.wikipedia....w#Basic_example
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