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Is there an example program that illustrates how a buffer overflow attack actually executes arbitrary code? (lemmy.dbzer0.com)

submitted 3 months ago* (last edited 3 months ago) by [email protected] to c/[email protected]

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I've found lots of examples in C of programs illustrating buffer Overflows, including those of pointer rewrites which has been of great help in understanding how a buffer overflow works and memory safety etc. but I've yet to be able to find an example illustrating how such a buffer overflow can rewrite a pointer in such a way that it actually results in code execution?

Is this just not a thing, or is my google-fu rust y? Tried ChatGPT and my local Mistral and they both seem unable to spit out precisely what I'm asking, so maybe I'm wording this question wrong.

If anyone in here knows, could point me in the right direction? Thanks y'all btw love this community 🧡

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[–] [email protected] 2 points 3 months ago* (last edited 3 months ago) (1 children)

Specifically I don’t know how to make a pointer at a predictable constant address so it’s stored address can be overwritten,

This is one of the things that I mentioned in my above comment on mitigating buffer overflow attacks, that address randomization is one of the mitigations. Are you trying to create an exploit that will function in such an environment?

If so, I'd still start out understanding how the attack works in a non-mitigated environment -- it's simpler -- and then learn about the mitigations and efforts to counter them.

[–] [email protected] 1 points 3 months ago

I agree, I think for now I'd like to try to create a demo exploit and exploitable program like this without considering ASLR et al. and then at some point in the future perhaps look at a return to libc type deal to understand that as well.