what is a good starting point for learning buffer overflow

Question

an article with examples and pointers would be great

Answer 1

Are you looking for an article that describes how to use the website? Most of the site's features are fairly self-explanatory and self-discoverable. If you find anything in particular to be confusing, you should probably file a feature request and ask for the behavior to be clarified or simplified.

You might also want to read about how reputation is calculated, and take a look at the FAQ. The FAQ isn't really full-featured yet, but I expect that it will be expected as the beta progresses. I certainly hope so.

Answer 2

Oh, if you're actually wanting information about actual stack overflows, I'd suggest starting with these wikipedia pages:

• http://en.wikipedia.org/wiki/Stack_overflow
• http://en.wikipedia.org/wiki/Stack_buffer_overflow
• http://en.wikipedia.org/wiki/Buffer_overflow

Answer 3

Well, the most famous piece of buffer overflows is Smashing the Stack for Fun and Profit.

Answer 4

the basics are pretty simple, you've got a buffer ( in the heap or stack ). This buffer is unchecked for bounds ( that is, you can write more than you should and the program will let you). If you write out of its bounds, you are writing other parts of memory that programs use. For example, if you have a function that just has one local array, and you write 1 more byte than the length of the array, you are writing the EBI pointer ( this is the bottom of the stack pointer), if you write 2 bytes more, you writing over the function pointer (if you overwrite this pointer with the hex address of another function, you can make that function call any function you want!). That's the basics, it get a lot more complex, like writing shell_code exploits, etc, but i'll leave the explanation for later.

Heres the phrack article for smashing the stack: http://www.csm.ornl.gov/~dunigan/smash.txt

Heres an article called

"Writing buffer overflow exploits - a tutorial for beginners", its pretty decent and fairly comprehensible. http://mixter.void.ru/exploit.html