CyberHunter
// Other services

Port 3805: ThorGuard Server Port

Port 3805 is assigned by IANA to tcpdataserver (ThorGuard Server Port).

3805

How tcpdataserver works

Other services
client:3805tcpdataserverresponse client:3805tcpdataserverresponse

The client sends a request to port 3805 and the tcpdataserver service answers.

Transport
TCP · UDP
Exposure risk
not rated depends on the program listening
Encryption
Unknownnot stated by the registry
IANA status
Assigned1 registered service
Range
Registered (1024-49151)
01 Security

Is port 3805 dangerous?

We have no specific security note for port 3805. Its risk depends on the program actually listening on it. General advice for other services services:

  • Close the port if nothing on the host needs it.
  • Identify the process that listens on it (commands below) before opening it in a firewall.
  • Expose a service only to the networks that use it.
02 Registry

IANA registry entries for port 3805

ServicePortTransportDescriptionReferenceUpdated
tcpdataserver 3805 TCP, UDP ThorGuard Server Port - 2004-02

// source: IANA service name and port number registry

03 Check it

Which program uses port 3805, and is it reachable?

Linux

sudo ss -ltnup 'sport = :3805'      # process listening on 3805
sudo lsof -nP -i :3805

macOS

sudo lsof -nP -i :3805

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 3805 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 3805
netstat -ano | findstr :3805

From another machine

nmap -p 3805 -sV <host>
sudo nmap -sU -p 3805 <host>
nc -zv <host> 3805

Block it in the firewall

sudo ufw deny 3805/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 3805" -Direction Inbound -LocalPort 3805 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 3805 used for?

Port 3805 is assigned by IANA to tcpdataserver (ThorGuard Server Port).

Is port 3805 TCP or UDP?

Port 3805 is registered for TCP and UDP.

Is it safe to open port 3805?

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. Close the port if nothing on the host needs it.

How do I check if port 3805 is open?

On Linux run "ss -ltnup 'sport = :3805'", on macOS "lsof -nP -i :3805", and on Windows "netstat -ano | findstr :3805" to see the local process. From another machine, "nmap -p 3805 <host>" shows whether it is reachable.

05 Related