Re: Overflowing Scripts fail to work

[Bill Weiss <houdini+pen-test () clanspum net>]

Paul Sebastian Ziegler(psz () observed de)@Sat, Apr 22, 2006 at 10:30:43AM +0200:
> Hallo list!
>
> I've been on this for quite some time and after failing to find out
> anything on the Internet I've finally decided to propose this question
> here. Any help would be greatly appreciated!
>
> Due to interest I have started to try to understand
> buffer-overflow-attacks. The theory is fine with me. But now I'm getting
> quite some trouble when trying to write exploiting scripts.
>
> Let me show you what I mean:
(code and example runs cut)

Using your C code and the same python code:

(%:~/tmp)- ./a.out `python -c "print 'A' * 524"`
AAAAAAA (lots of As cut)
a.out: stack smashing attack in function main()
zsh: abort      ./a.out `python -c "print 'A' * 524"`
(%:~/tmp)- python
Python 2.4.2 (#1, Oct 16 2005, 00:06:10)
[GCC 3.3.6 (Gentoo Hardened 3.3.6, ssp-3.3.6-1.0, pie-8.7.8)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
> > > import os
> > > os.system("./a.out " + ("A" * 524))
AAAAAAA (again, lots of As)
a.out: stack smashing attack in function main()
6
> > >
(%:~/tmp)- python vuln.py
AAAAAAA (As galore)
a.out: stack smashing attack in function main()
(%:~/tmp)

Gentoo with kernel 2.6.12-gentoo-r10, GCC 3.3.6 (Gentoo Hardened 3.3.6,
ssp-3.3.6-1.0, pie-8.7.8), Python 2.4.2 built with this GCC.

The Hardened stuff is why I'm seeing "stack smashing attack", but I can't
imagine why this would be causing a failure where yours isn't (while
running from within python).

Unless the newer kernels added something here (which I doubt), it should
be working for you.  We're on almost the same build.

-- 
Bill Weiss

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