UDP Port 23 – Telnet (Legacy Remote Terminal)

About UDP Port 23

Port 23 carries the IANA assignment for telnet. The IANA description reads: ‘Telnet’. This port appears in 1 IDS rule and does not have notable malware activity indicators in our data.

IDS Rule References

1 IDS / security rule reference UDP port 23. Presence in IDS rules does not mean traffic on this port is malicious. These are patterns security tools monitor.

Rule categories (top 1): attempted-admin (1).

Sample rule descriptions for UDP port 23:

• SERVER-OTHER NETGEAR TelnetEnable attempt

Data Sources

This information is compiled from: IANA Service Name and Transport Protocol Port Number Registry, Emerging Threats Open Ruleset (BSD 2-Clause / GPLv2 per SID range), and Snort Community Rules (GPLv2).