TCP Port 541 – uucp-rlogin

About TCP Port 541

The Internet Assigned Numbers Authority (IANA) registers port 541 for uucp-rlogin. The IANA description reads: ‘uucp-rlogin’. This port appears in 6 IDS rules and does not have notable malware activity indicators in our data.

IDS Rule References

6 IDS / security rules reference TCP port 541. Treat that number as context, not a danger score. Many detection rules are written against groups of ports rather than one service, web ports especially, so common web alternate ports inherit large counts while genuinely sensitive services can show few rules or none. Presence in IDS rules does not mean traffic on this port is malicious.

Rule categories (top 1): attempted-admin (6).

Sample rule descriptions for TCP port 541:

• ET EXPLOIT Fortinet FGFM Arbitrary Code Execution via Externally-Controlled Format String (CVE-2024-23113)
• ET EXPLOIT Fortinet FortiManager Unauthenticated Get File Transfer Handle
• ET EXPLOIT Fortinet FortiManager File Transfer Handle Response
• ET EXPLOIT Fortinet FortiManager Unauthenticated Remote Code Execution (CVE-2024-47575) M1
• ET EXPLOIT Fortinet FortiManager Unauthenticated Open Server-Side Channel

Data Sources

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