Port Intelligence Profile
Port 23: Telnet
Analyze default service protocols, historical security vulnerabilities, hardening methods, and firewall rules for port 23.
Default Service
Telnet
Protocol
TCP
Risk Level
Critical
Port Range
System (1-1023)
1. Port Purpose & Usage
Port 23 is registered for Telnet network communication.
2. Security Risks & Vulnerability Profiles
Exposing port 23 publicly increases attack surface. Ensure proper firewall filters and authentication checks are enforced.
3. Hardening & Mitigation Checklist
1
Restrict access to port using local firewall rules.
2
Disable standard passwords; use cryptographic authentication if supported.
4. Firewall Command Examples
Use the following system configurations to restrict open port exposure on Linux hosts:
# UFW: Deny public access to port 23
ufw deny 23/tcp
Further Analysis
Remote Administration Ports
Ports often operate in clusters. When analyzing a service on Port 23, security engineers typically check the status of these related ports.