- Do not expose remote administration directly: use a VPN or a zero-trust access proxy.
- Require MFA or key-based authentication and lock out brute-force attempts.
- Log every login and alert on new source addresses.
Port 4915: Fibics Remote Control Service
Port 4915 is assigned by IANA to frcs (Fibics Remote Control Service).
4915
How frcs works
Remote accessThe client opens a session to port 4915: each command typed is sent to the server, which runs it and returns the output.
- Transport
- TCP
- Exposure risk
- not rated depends on the program listening
- Encryption
- Unknownnot stated by the registry
- IANA status
- Assigned1 registered service
- Range
- Registered (1024-49151)
- Category
- Remote access
Is port 4915 dangerous?
We have no specific security note for port 4915. Its risk depends on the program actually listening on it. General advice for remote access services:
IANA registry entries for port 4915
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| frcs | 4915 | TCP | Fibics Remote Control Service | - | 2009-04-17 |
| - | 4915 | - | Reserved | - | - |
// source: IANA service name and port number registry
Which program uses port 4915, and is it reachable?
Linux
sudo ss -ltnup 'sport = :4915' # process listening on 4915
sudo lsof -nP -i :4915macOS
sudo lsof -nP -i :4915
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 4915 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 4915 netstat -ano | findstr :4915
From another machine
nmap -p 4915 -sV <host> nc -zv <host> 4915
Block it in the firewall
sudo ufw deny 4915/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 4915" -Direction Inbound -LocalPort 4915 -Protocol TCP -Action Block # Windows
What is port 4915 used for?
Port 4915 is assigned by IANA to frcs (Fibics Remote Control Service).
Is port 4915 TCP or UDP?
Port 4915 is registered for TCP.
Is it safe to open port 4915?
It depends on the program that listens on it. Open it only for a service you know and only to the networks that need it. Do not expose remote administration directly: use a VPN or a zero-trust access proxy.
How do I check if port 4915 is open?
On Linux run "ss -ltnup 'sport = :4915'", on macOS "lsof -nP -i :4915", and on Windows "netstat -ano | findstr :4915" to see the local process. From another machine, "nmap -p 4915 <host>" shows whether it is reachable.
Other remote access ports
:22 SSH tcp · udp · sctp · moderate risk :3389 RDP tcp · udp · critical risk :23 Telnet tcp · udp · critical risk :5900 VNC tcp · udp · critical risk :5985 WinRM (HTTP) tcp · udp · high risk :5986 WinRM (HTTPS) tcp · udp · high risk :10000 Webmin tcp · udp · high risk :89 SU/MIT Telnet Gateway tcp · udp