Port 4135Classic Line Database Server Attach

Port 4135 is assigned to the Classic Line Database Server Attach service over TCP and UDP.

transport: tcp · udp
in transit: cleartext
assignment: official
risk: 1/10
lookups: 0

also known as cl-db-attach

Technical Details

what runs on :4135

Classic Line Database Server Attach is registered on port :4135 over tcp and udp. 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 found open rarely. What's listening is often not the registered service, so check before you assume.

find what's listening on :4135

this machine

# linux
sudo ss -tulpn 'sport = :4135'

# macos / bsd
sudo lsof -nP -i :4135

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :4135

another host

nmap -sV -p T:4135 <host>
sudo nmap -sU -sV -p U:4135 <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 :4135

risk score

1/ 10safe

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

databases averages 3.9 across 130 ports — this one sits 2.9 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 :4135 yet

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

Record

iana registry entry

port: :4135
service: Classic Line Database Server Attach
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: Databases
usage: TCP and UDP port 4135 are assigned to the Classic Line Database Server Attach service. IANA records no registrant or deployment details for this assignment.
lookups: 0rank 993
added: 2026-09-05
updated: 2026-09-05
references: IANA service name registry — port 4135

Something wrong?

This record is maintained by the engineers who use port 4135. Every field on it is editable — change what's wrong, say how you know, and a reviewer publishes it, usually within a minute. Last touched 2026-09-05.

01edit any field on a page of its own
02a model checks it for accuracy and spam
03clean and confident goes live immediately

edit this record →back to the registry

Related Ports

all 130 in databases →

the 8 most looked-up other ports in databases — 130 ports carry that label.

port	service	proto	category	risk	views
:8882	Atlasz Secure App Server	TCP	Web Services	caution	66.9k
:9001	ETL Service Manager	TCPUDP	Databases	caution	28.6k
:2484	Oracle SSL Listener	TCPUDPtls	Security	caution	25.0k
:5495	Applix TM1 Admin	TCP	Databases	caution	24.8k
:591	FileMaker Web Sharing	TCP	Web Services	caution	23.1k
:1521	Oracle TNS Listener	TCP	Security	caution	19.6k
:21001	AMLFilter Admin	TCP	Security	caution	19.2k
:18206	Audition FAM DB	TCPUDP	Databases	caution	19.1k

risk mix of the 8 listed

caution100%

1 of 8 encrypted

Port :4135Classic Line Database Server Attach

Technical Details

Security Information

Related Ports

Port 4135Classic Line Database Server Attach