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TCP
Vulnerable
1433 Microsoft SQL Server
Port 1433 is the default listener for Microsoft SQL Server instances and application data access.
Security Context
Port 1433 is high-risk when broadly exposed. Treat it as an attack-surface decision, not just a connectivity setting, and confirm whether the listener truly needs to be reachable.
- !Internet-exposed database listeners are frequent brute-force and exploitation targets.
Nmap Check
Use a version probe first so you confirm whether the expected service is really what is listening on this port.
nmap -sV -p 1433 <host>Firewall Commands
UFW
sudo ufw allow 1433/tcpiptables
sudo iptables -A INPUT -p tcp --dport 1433 -j ACCEPT