CyberHunter
// Other services

Port 7781: accu-lmgr

Port 7781 is assigned by IANA to accu-lmgr (accu-lmgr).

7781

How accu-lmgr works

Other services
client:7781accu-lmgrresponse client:7781accu-lmgrresponse

The client sends a request to port 7781 and the accu-lmgr 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 7781 dangerous?

We have no specific security note for port 7781. 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 7781

ServicePortTransportDescriptionReferenceUpdated
accu-lmgr 7781 TCP, UDP accu-lmgr - -

// source: IANA service name and port number registry

03 Check it

Which program uses port 7781, and is it reachable?

Linux

sudo ss -ltnup 'sport = :7781'      # process listening on 7781
sudo lsof -nP -i :7781

macOS

sudo lsof -nP -i :7781

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 7781 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 7781
netstat -ano | findstr :7781

From another machine

nmap -p 7781 -sV <host>
sudo nmap -sU -p 7781 <host>
nc -zv <host> 7781

Block it in the firewall

sudo ufw deny 7781/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 7781" -Direction Inbound -LocalPort 7781 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 7781 used for?

Port 7781 is assigned by IANA to accu-lmgr (accu-lmgr).

Is port 7781 TCP or UDP?

Port 7781 is registered for TCP and UDP.

Is it safe to open port 7781?

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 7781 is open?

On Linux run "ss -ltnup 'sport = :7781'", on macOS "lsof -nP -i :7781", and on Windows "netstat -ano | findstr :7781" to see the local process. From another machine, "nmap -p 7781 <host>" shows whether it is reachable.

05 Related