Microsoft SQL (MSSQL)

Microsoft’s proprietary Relational Database Management System (RDBMS).

It has strong native support for .NET.

Some versions can run on MacOS or Windows, but most run exclusively on Windows.

Client applications

The database can be managed remotely by the client applications:

• SQL Server Management Studio (SSMS)
• mssql-cli
• SQL Server PowerShell
• HeidiSQL
• SQLPro
• Impacket’s mssqlclient.py.

Default system databases

• 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

Security

Dangerous settings include:

• 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
• Weak & default sa credentials. Admins may forget to disable this account