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Using a buffer overflow, I have been able to override return addresses. But the problem is that Windows addresses contain zeros at the beginning (e.g. 0x00401020). As a result, the objdump of any C binary will contain zero's. This makes it very difficult to execute shellcode inside a buffer as a shellcode cannot contain zero's for it to work.

Has anyone done this sort of thing? It does not matter even if the exploit is printing hello-world: is it possible?

  • Isn't Objdump a *nix utility? What happens if you used a Windows-specific debugger? – schroeder May 28 '14 at 15:28
  • It might there on *nix as well but I have used it on windows as well. The issue is not related to debugger whether it is Windbg or Immunity Debugger. – Noname May 28 '14 at 16:36
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You should be able to remove the leading zeros, as 0x00401020 = 0x401020.

  • nopes , this does not work. the shell code fails if you simply remove zero's. – Noname May 28 '14 at 14:05
  • Does it fail because of the missing zeros, or does it fail because removing the zeros change the size of the shellcode? – Corneliux May 28 '14 at 14:21
  • Yes the size of shellcode changes as well as the 00's are replaced by next two digits/characters. This changes the shell code and renders it useless. – Noname May 28 '14 at 16:44

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