Network Port: 1433
Network Port Reference Guide
Registered Service Name
Microsoft SQL Server
Transport Protocol
TCP
Functional Overview
Port 1433 is the default port utilized by Microsoft SQL Server (MSSQL) database engines.
Security Risks & Vulnerabilities
High risk database target. Exposing Port 1433 directly to the public internet invites remote code execution (RCE) attempts and SQL injection probes. Restrict to internal VPC or VPN networks.
How to audit network port status
1. Scan Open Ports: Use our Port Scanner utility to verify if this port is actively listening on your host.
2. Verify Encryption: Audit the service layer to confirm SSL/TLS is protecting transmission payload.
3. Hardening Rules: Apply the firewall instructions below to shut down unauthorized inbound ports.
UFW Firewall Rules
Allow Command
sudo ufw allow 1433/tcp
Block Command
sudo ufw deny 1433/tcp
iptables Firewall Rules
Allow Command
sudo iptables -A INPUT -p tcp --dport 1433 -s 10.0.0.0/8 -j ACCEPT
Block Command
sudo iptables -A INPUT -p tcp --dport 1433 -j DROP