CyberHunter
Local dataset, no network
// Other services

Port 3786: VSW Upstrigger port

Port 3786 is assigned by IANA to upstriggervsw (VSW Upstrigger port).

3786

How upstriggervsw works

Other services
client:3786upstriggervswresponse client:3786upstriggervswresponse

The client sends a request to port 3786 and the upstriggervsw 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 3786 dangerous?

We have no specific security note for port 3786. 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 3786

ServicePortTransportDescriptionReferenceUpdated
upstriggervsw 3786 TCP, UDP VSW Upstrigger port - 2003-07

// source: IANA service name and port number registry

03 Check it

Which program uses port 3786, and is it reachable?

Linux

sudo ss -ltnup 'sport = :3786'      # process listening on 3786
sudo lsof -nP -i :3786

macOS

sudo lsof -nP -i :3786

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 3786 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 3786
netstat -ano | findstr :3786

From another machine

nmap -p 3786 -sV <host>
sudo nmap -sU -p 3786 <host>
nc -zv <host> 3786

Block it in the firewall

sudo ufw deny 3786/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 3786" -Direction Inbound -LocalPort 3786 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 3786 used for?

Port 3786 is assigned by IANA to upstriggervsw (VSW Upstrigger port).

Is port 3786 TCP or UDP?

Port 3786 is registered for TCP and UDP.

Is it safe to open port 3786?

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 3786 is open?

On Linux run "ss -ltnup 'sport = :3786'", on macOS "lsof -nP -i :3786", and on Windows "netstat -ano | findstr :3786" to see the local process. From another machine, "nmap -p 3786 <host>" shows whether it is reachable.

05 Related

Latest vulnerability news

All news