Port 3437Autocue Directory Service

Port 3437 is assigned to the Autocue Directory Service, with no widely established deployment or protocol behavior known.

transport
tcp · udp

2 transports registered

in transit
cleartext

payload readable on path

assignment
official

registered with iana

risk
1/10

safe

lookups
0

rank 993 of 4,697 · top 21%

also known as autocueds

Technical Details

what runs on :3437

Autocue Directory Service is registered on port :3437 over tcp and udp to Geoff Back, assigned March 2002. We don't have a technical write-up for it beyond the IANA registry entry.

In nmap's internet-wide scan data this port is never observed open, so if it's open on your network it's more likely a custom or misconfigured service than the registered one.

find what's listening on :3437

this machine
# linux
sudo ss -tulpn 'sport = :3437'

# macos / bsd
sudo lsof -nP -i :3437

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :3437
another host
nmap -sV -p T:3437 <host>
sudo nmap -sU -sV -p U:3437 <host>

run it? the handshake, the implementations you meet in the wild and the flags that matter come from the engineers who do.

add technical details

Security Information

exposure of :3437

risk score

1/ 10safe

routine exposure. this port is rarely the way in on its own — keep it patched and logged and move on.

network services averages 2.7 across 1,398 ports — this one sits 1.7 below.

in transit

cleartext

credentials and payloads are readable by anyone on path

assignment

official

registered with iana for this service — scanners fingerprint it by number

reachable over

tcp · udp

udp is connectionless — source addresses are trivially spoofed and it is a reflection favourite

security overview

no security notes recorded for :3437 yet

known exploits, hardening advice, what a compromise looks like — suggest an edit if you know its exposure.

the 8 most looked-up other ports in network services — 1,398 ports carry that label.

risk mix of the 8 listed

  • caution100%

0 of 8 encrypted