Internet-Security raven logo internet-security.com

TCP 1433

ProtocolTCP
Port1433
LabelsMicrosoft SQL Server database management system (MSSQL) server

Synopsis

  • TCP 1433 is the default port for Microsoft SQL Server’s Database Engine, carrying the Tabular Data Stream (TDS) protocol.
  • Microsoft SQL Server Management Studio (SSMS), sqlcmd, and ODBC/JDBC/ADO.NET drivers connect to SQL Server over 1433 by default.
  • Azure SQL Database exposes its public endpoint on 1433, and managed services like Amazon RDS for SQL Server and Google Cloud SQL for SQL Server use 1433 unless reconfigured.
  • Enterprise products that store data in SQL Server—such as Microsoft SharePoint, System Center Configuration Manager (SCCM), and Microsoft Dynamics—connect to backend SQL Server instances on 1433 in default deployments.
  • The official Microsoft SQL Server container images (mcr.microsoft.com/mssql/server) listen on 1433/tcp by default.
  • Third-party SQL Server–compatible drivers (e.g., jTDS, FreeTDS) use 1433 when reaching SQL Server endpoints.
  • Security note: Port 1433 is frequently targeted for scanning and brute-force attacks (especially against the “sa” account) and abused when exposed SQL Server instances have weak credentials or dangerous features like xp_cmdshell enabled.

Observed activity

Last 30 days Detailed chart

More information