bomonike

What ports are open on my Mac, Linux, and Windows machines?

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Overview

ports-open.png Here is how to see what ports are open listening on a server.

This is perhaps the most important potential vulnerability.

Having ports listening to outside traffic also takes CPU effort, which consumes electricity and thus reduce battery life.

Port numbers assigned

PAT (Port Address Translation) maps ports.:

Port 3389 is used for communicating with Microsoft’s RDP (Remote Desktop Protocol) on Windows machines.

Common TCP Ports in layer 4: REMEMBER

Service

TCP Ports

UDP Ports

SMB

445

445

NetBIOS

137, 139

137, 138

LDAP

389

389

LDAP over TLS

636

Global catalog LDAP

3268

Global catalog LDAP over TLS

3269

NFS

111, 2049, 4045, 1110

111, 2049, 4045, 1110

Kerberos

88, 464, 543, 544, 749, 751

88, 464, 749, 750, 751, 752

RPC

111, 135, 530

111, 135, 530

WINS

1512, 42

1512, 42

DHCP

67, 68, 546, 547

67, 68, 546, 547

Syslog

601

514

Print services

515

Telnet

23

23

FTP

21

21

SSH

22

22

RDP

3389

3389

MongoDB

27017, 27018, 27019, 28017

SQL Server

1433

1434

MySQL

3306

PostgreSQL

5432

Oracle

1521, 1630

Elasticsearch

9300, 9200

HTTP

 80 80

HTTPS

 443 443



Spring Boot:

IP header protocol field REMEMBER

Spotlight on Network Utility to List Ports

Apple’s macOS Spotlight is like Window’s Search omni-box. *

  1. Press Command+Spacebar.

  2. Type the name of utilities that are buried, such as Network Utility.

  3. Click the keyboard return/enter key to launch the Network Utility app.

    port-open-network-util-601x331-72k

  4. Select the "Port Scan" tab.

  5. Enter the IP (such as 127.0.0.1), localhost, or domain name you wish to scan for open ports.

  6. Choose scan to see what ports the server responds to.

List open files = lsof

  1. In a Terminal command line:

    lsof -nP +c 15 | grep LISTEN

    PROTIP: If you’ll be using this often, create an alias such as listening.

    “lsof” is a contraction for “list open files”. Without any options specifications, lsof lists all open files belonging to all active processes.

    “-nP” is a combination of “n” for no resolution of IPs to hostnames using DNS and “P” for no resolution of Port names from numbers.

    This is because the command already takes several seconds to run.

    “+c 15” specifies command width of 15.

    Piping to grep filters out only lines containing “LISTEN”.

    A sample response:

    rapportd          615 wilsonmar    4u     IPv4 0xafaa508... TCP *:53150 (LISTEN)
rapportd          615 wilsonmar    5u     IPv6 0xafaa508... TCP *:53150 (LISTEN)
ControlCenter     697 wilsonmar   14u     IPv4 0xafaa508... TCP *:7000 (LISTEN)
ControlCenter     697 wilsonmar   15u     IPv6 0xafaa508... TCP *:7000 (LISTEN)
ControlCenter     697 wilsonmar   16u     IPv4 0xafaa508... TCP *:5000 (LISTEN)
ControlCenter     697 wilsonmar   17u     IPv6 0xafaa508... TCP *:5000 (LISTEN)
Stream\x20Deck   1332 wilsonmar   13u     IPv4 0xafaa508... TCP 127.0.0.1:28196 (LISTEN)
AMPDevicesAgent  3340 wilsonmar   10u     IPv4 0xafaa508... TCP *:49748 (LISTEN)
com.docker.back 19614 wilsonmar   33u     IPv4 0xafaa508... TCP *:53680 (LISTEN)
com.docker.back 19614 wilsonmar  131u     IPv6 0xafaa508... TCP *:8080 (LISTEN)
com.docker.back 19614 wilsonmar  158u     IPv6 0xafaa508... TCP *:5432 (LISTEN)
com.docker.back 19614 wilsonmar  159u     IPv6 0xafaa508... TCP *:8200 (LISTEN)
com.docker.back 19614 wilsonmar  160u     IPv6 0xafaa508... TCP *:1717 (LISTEN)
vpnkit-bridge   19710 wilsonmar    8u     IPv4 0xafaa508... TCP *:53680 (LISTEN)
grafana-server  23515 wilsonmar   17u     IPv6 0xafaa508... TCP *:3000 (LISTEN)

    rapportd is Apple’s

    AMPDevicesAgent may <a target=”_blank” href=”“>ask you for a password when you connect using USB the first time. It can cause 100% CPU usage. To avoid this, in iPhone Apple Music, uncheck the “automatically sync over wifi” box. To quit the process, go into Activity Monitor, find ‘AMPDevicesAgent’, select it and click on the information button, and quit the process. Then eject the iOS devices on Finder.

    ControlCenter listens when “AirPlay Receiver” is turned on in System Preferences -> “Sharing”. Control Center stops listening to those ports when that’s turned off.

    vpnkit-bridge goes away after Docker Desktop is stopped. The process is used by Docker Desktop under the hood. The process has caused 100% memory usage, and Fixed in Docker 2.3. It’s at file /Applications/Docker.app/Contents/MacOS/vpnkit-bridge.

    grafana and other background services can be stopped:

    brew services list
brew services stop grafana

  2. https://www.joesandbox.com/#mac creates a report such as this.

  3. NOTE: All options are shown by this command:

    lsof -h

    See http://www.thegeekstuff.com/2012/08/lsof-command-examples

  4. Drag your Terminal window wider to remove word-wrap.

    COMMAND           PID USER   FD      TYPE DEVICE                   SIZE     NODE     NAME
mongod            429  mac    6u     IPv4 0xeef754dd0b1f6a1b        0t0      TCP 127.0.0.1:27017 (LISTEN)
2BUA8C4S2C.com.   437  mac   11u     IPv4 0xeef754dd0b1f7c0b        0t0      TCP 127.0.0.1:6258 (LISTEN)
2BUA8C4S2C.com.   437  mac   12u     IPv6 0xeef754dd02830d03        0t0      TCP [::1]:6258 (LISTEN)
2BUA8C4S2C.com.   437  mac   13u     IPv4 0xeef754dd0bcc3313        0t0      TCP 127.0.0.1:6263 (LISTEN)
2BUA8C4S2C.com.   437  mac   14u     IPv6 0xeef754dd028307c3        0t0      TCP [::1]:6263 (LISTEN)
Resilio\x20Sync   563  mac    7u     IPv4 0xeef754dd0d29c313        0t0      TCP *:49387 (LISTEN)
Skype             743  mac   20u     IPv4 0xeef754dd2d469313        0t0      TCP 10.0.0.2:2301 (LISTEN)
SketchMirrorHel  1912  mac    7u     IPv4 0xeef754dd12dda63b        0t0      TCP *:56989 (LISTEN)
SketchMirrorHel  1912  mac    8u     IPv6 0xeef754dd02830283        0t0      TCP *:56989 (LISTEN)
SketchMirrorHel  1912  mac   10u     IPv4 0xeef754dd11ecaf33        0t0      TCP *:56990 (LISTEN)
ruby            13444  mac    7u     IPv4 0xeef754dd18739c0b        0t0      TCP 127.0.0.1:4000 (LISTEN)
nginx           20244  mac    6u     IPv4 0xeef754dd1158563b        0t0      TCP *:8080 (LISTEN)
nginx           20245  mac    6u     IPv4 0xeef754dd1158563b        0t0      TCP *:8080 (LISTEN)
Dropbox         21014  mac  114u     IPv6 0xeef754dd05928d03        0t0      TCP *:17500 (LISTEN)
Dropbox         21014  mac  115u     IPv4 0xeef754dd079ce313        0t0      TCP *:17500 (LISTEN)
Dropbox         21014  mac  157u     IPv4 0xeef754dd20427a1b        0t0      TCP 127.0.0.1:17600 (LISTEN)
Dropbox         21014  mac  163u     IPv4 0xeef754dd0e9f763b        0t0      TCP 127.0.0.1:17603 (LISTEN)

“FD” column lists File Descriptors. “u” is for read and write mode. “r” for read only, “w” for write-only.

Linux requires root on operations for well-known ports below 1024.

Protocols

TCP (Transmission Control Protocol) is the most commonly used protocol on the Internet and any TCP/IP network. TCP enables two hosts to establish a connection and exchange streams of data. TCP guarantees delivery of data and that packets will be delivered in the same order in which they were sent. Guaranteed communication/delivery is the key difference between TCP and UDP on ort 53.

UDP (Datagram Protocol) is connectionless and does not guarantee reliable communication; it’s up to the application that received the message to process any errors and verify correct delivery. UDP is often used with time-sensitive applications, such as audio/video streaming, where dropping some packets is preferable to waiting for delayed data.

Processes Tour

NOTE: Drag the scroll bar to see what is beyond what is displayed.

     0t0      TCP 127.0.0.1:27017 (LISTEN)

mongod is MongoDB listening on port 27017.

I should keep that closed unless I need it.

https://www.mkyong.com/mongodb/mongodb-allow-remote-access/

In Node, close all connections when the app closes completely:

process.on('SIGINT', function() {
  mongoose.connection.close(function () {
    console.log('Mongoose disconnected on app termination');
    process.exit(0);
  });
});

2BUA8C4S2C

When I search for “2BUA8C4S2C” I see “2BUA8C4S2C.com.agilebits” in folder /Users/mac/Library/Group Containers

This says This port is used only on the loopback interface (127.0.0.1) for the 1Password extension to talk to the 1Password Agent. It should be safe to firewall it from any sources other than 127.0.0.1. If you do a packet capture on lo0 and then filter by tcp.port == 6258 you can see what traffic is being passed. Nothing is transmitted in the clear.

Skype I don’t mind keeping open. I use it a lot.

Dropbox - why does it need to be kept open?

I’ll use just their web page when I need it.

See https://www.dropbox.com/help/41

Resilio\x20Sync I used once to get a file.

In Resilio Preferences, uncheck “Start Resilio Sync on startup”.

SketchMirrorHel

XMPP ports 56989 and 56990

For a list of processes on Mac:

Don’t visit http://www.westwind.com/reference/OS-X/background-processes.html

ftp (tftp) should not appear.

NMAP

Scan other machines

  1. Install

    brew install nmap

    (Zenmap is the GUI)

  2. There are a lot of options

    nmap -h

    The format:

    nmap [scan type] [options] {target specification}

  3. There are a lot of options

    nmap -h

  4. Scan for vulnerabilities using nmap scripts.

    nmap -P0 35.87.188.71

  5. Scan for vulnerabilities using vulnerability scanners:

    OpenVAS

  6. Scans for versions of applications and operating systems. Compare those against known vulnerabilities and exploits.

Devices on the Internet with open ports are indexed by Shodan.io.

SNR (software defined radios)

Resources

Learn basic hardware hacking with UbertoothOne and HackRF One.

US Government has free training at https://ics-cert-training.inl.gov/learn

https://www.wikiwand.com/en/Lsof

https://danielmiessler.com/study/lsof/#gs.3YHJpiA

https://netadmintools.com/html/lsof.man.html

Zeek.org (formerly Bro) and/or snort.org

Network Intrusion detection systems (NIDS)

AlienVault Open Source SIEM (OSSIM) with Open Threat Exchange (OTX) Security Information and Event Management (SIEM) software.

Honeypots

Commercial Honeypot software:

Certified Ethical Hacker (CEH)

https://learning.oreilly.com/videos/-/9780137446797/ Complete Video Course, 3rd Edition By Omar Santos and Nick Garner from Pearson November 2021

pfSense

pfSense CE (Community Edition)

https://www.pfsense.org/ from Rubicon Communications, LLC (Netgate) started in 2008 as the Monowall firewall based on BSD operating system.

https://www.pfsense.org/products/ on ARM and Intel Atom hardware

https://www.youtube.com/watch?v=Qr1nUxdzcbA on David Bombal’s channel by Tom Lawrence of lawrencesystems.com <a target=”_blank” href+https://www.youtube.com/watch?v=1E6fYKlQKa0”>VIDEO</a>: vs. Unifi USG/UXG, UDM

https://www.netgate.com/training/pfsense-fundamentals-and-advanced-application To get pfSense Plus Fundamentals certification, first correctly answer 75% of 90 multiple-choice questions in 60 minutes. Then schedule and complete the nine labs of the Practical assignment over two-days with 20 others. On day one, complete labs 1-5 and pause for the instructor to grade your progress. If you pass, continue to lab 6. When complete, the instructor will grade lab 6. A passing grade means you can return the following day to complete labs 7-9.

Proxmox

Tutorials

https://www.youtube.com/watch?v=xmpYfyNmWbw CompTIA Network+ Full Course FREE [23+ Hours]

More on OSX

This is one of a series on Mac OSX: