TCP Port 513 – login
About TCP Port 513
Port 513 is registered with the Internet Assigned Numbers Authority (IANA) for login. The IANA description reads: ‘remote login a la telnet; automatic authentication performed based on priviledged port numbers and distributed data bases which identify "authentication domains"’. This port appears in 8 IDS rules and does not have notable malware activity indicators in our data.
IDS Rule References
8 IDS / security rules reference TCP port 513. Presence in IDS rules does not mean traffic on this port is malicious. These are patterns security tools monitor.
Rule categories (top 4): attempted-admin (3), bad-unknown (2), unsuccessful-user (2), attempted-user (1).
Sample rule descriptions for TCP port 513:
- PROTOCOL-SERVICES rlogin LinuxNIS
- PROTOCOL-SERVICES rlogin bin
- PROTOCOL-SERVICES rlogin echo++
- PROTOCOL-SERVICES Unix rlogin froot parameter root access attempt
- PROTOCOL-SERVICES rlogin login failure
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).