Network & services

telnet (23) not exposed

Databases, remote access and other services reachable from the internet; blocklist status.

Why it matters

Internet-wide scanners find an open service within minutes. Exposed databases and remote-access services are the most common starting point of data breaches and ransomware.

How to fix it

Moderate · a few hours

Decide whether the service needs to be reachable from the internet at all - usually it does not.
Block the port in the server or cloud firewall, allowing only trusted IP addresses or a VPN.
Make the service listen on localhost or a private network only.
Make sure it requires strong authentication even inside the network.

ufw (Ubuntu)

sudo ufw deny <port>/tcp
# or allow one trusted address only:
sudo ufw allow from 203.0.113.10 to any port <port> proto tcp

Redis (redis.conf)

bind 127.0.0.1 ::1
protected-mode yes
requirepass <long-random-password>

MongoDB (mongod.conf)

net:
  bindIp: 127.0.0.1
security:
  authorization: enabled

MySQL (my.cnf)

[mysqld]
bind-address = 127.0.0.1

How we test it

The check runs from the public internet as part of every scan, read-only and without touching your data. If it fails, your report shows the evidence that proves it - the record, header, file or banner we observed - together with the fix above, tailored to the issue we found.

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