Shellcode Injection

Almost every program nowadays is compiled with W^X (--no_execstack) by default which means the memory is not executable and writable at once (Windows equivalent is DEP). Still a good example of how a basic overflow can lead to arbitrary code execution. A follow-up post using ROP or return-to-libc would be interesting, with W^X enabled.

My favourite resource for these types of exploits used to be phiral.com (see Wayback Machine circa March 2007 [1], since it doesn&#x27;t exist anymore), belonging to author Jon Erickson who wrote &quot;Hacking: the Art of Exploitation&quot; [2].<p>[1] <a href="https:&#x2F;&#x2F;web.archive.org&#x2F;web&#x2F;20070305111749&#x2F;http:&#x2F;&#x2F;phiral.com&#x2F;" rel="nofollow">https:&#x2F;&#x2F;web.archive.org&#x2F;web&#x2F;20070305111749&#x2F;http:&#x2F;&#x2F;phiral.com...</a><p>[2] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Hacking:_The_Art_of_Exploitation" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Hacking:_The_Art_of_Exploitati...</a>

The same author refers to another article of him, in which he explains the basics of buffer overflows quite nice. <a href="https:&#x2F;&#x2F;dhavalkapil.com&#x2F;blogs&#x2F;Buffer-Overflow-Exploit&#x2F;" rel="nofollow">https:&#x2F;&#x2F;dhavalkapil.com&#x2F;blogs&#x2F;Buffer-Overflow-Exploit&#x2F;</a>

Here are 2 good courses on Assembly and Shellcoding on x86 and x86_64 if you are interested:<p><a href="http:&#x2F;&#x2F;www.pentesteracademy.com&#x2F;topics?v=nhr" rel="nofollow">http:&#x2F;&#x2F;www.pentesteracademy.com&#x2F;topics?v=nhr</a>

Why &quot;echo 0 | dd of=foo&quot; and not simply &quot;echo 0 &gt; foo&quot;?

I must be missing something. If you can create an executable which is suid you already have root...

&gt; ... -fno-stack-protector -z execstack<p>Does anyone know how common stack protector is in the wild?