Hi Wade,
Thanks for your response. Shellcode is native machine code. It is not shell script code. See http://en.wikipedia.org/wiki/Shellcode -----Original Message----- From: Wade Richards <w...@wabyn.net> To: Brchk05 <brch...@aim.com> Cc: debian-security@lists.debian.org <debian-security@lists.debian.org> Sent: Sun, Oct 10, 2010 11:59 am Subject: Re: non-executable stack (via PT_GNU_STACK) not being enforced The noexecstack option has no affect on shell code or any other interpreted language. It only prevents native code (aka machine code) from executing. --- Wade On 2010-10-10, at 6:53, Brchk05 <brch...@aim.com> wrote: I am running Debian 2.6.26-21lenny4 and I am puzzled by an issue with the enforcement of page permissions. I have written a simple program with a basic buffer overflow and compiled two versions using gcc: one with -z execstack and another with -z noexecstack. So, to verify that the option takes: For the -z execstack version: $ readelf -l a.out | grep -i -A1 stack GNU_STACK 0x000000 0x00000000 0x00000000 0x00000 0x00000 RWE 0x4 For the -z noexecstack version: $ readelf -l a.out | grep -i -A1 stack GNU_STACK 0x000000 0x00000000 0x00000000 0x00000 0x00000 RW 0x4 However, I am able to inject and execute shellcode from a stack local character buffer in both versions. Is there another system option I am unaware of that affects enforcement? Is enforcement not supported for my system version? Thanks for your help.
