In computer networking a port is a software construct serving as a communications endpoint in a computer's host OS.

learn more… | top users | synonyms

6
votes
3answers
127 views

Risk of running services on ports >1024

In a Reddit thread on securing SSH access to a Raspberry Pi, one commenter recommended running SSH on a non-standard port of 8123. Another commenter had this to say on the matter: Don't change ...
0
votes
1answer
41 views

Open ports on router

I have a TP-Link TD W8970 modem/router. Just for fun i tried to perform a port scan on it. I found this: $ nmap -p 1-65535 -n 192.168.1.1 Starting Nmap 6.00 ( http://nmap.org ) at 2016-01-21 16:17 ...
3
votes
0answers
79 views

DDoS Mitigation - Whitelist or Blacklist Incoming Ports?

For a network offering webservices, I have had recommendations to blacklist a couple of common incoming ports, such as UDP 53, to combat the increasing load from DDoS. I'm wondering if it makes more ...
0
votes
0answers
2 views

Incoming connections to Skype in 50656 and 45623 ports [migrated]

I've seen many attemps connections from different and unknown IP's to my mac computers (two different Macs) to 45623 and 50656 ports. Little Snitch says it's trying to connec to Skype but I can't ...
0
votes
0answers
18 views

Raspberry IP email on boot bypass [migrated]

I have configured my Raspberry Pi2 B+ to send an email through SMTPS (smtp.gmail.com:587) after the boot with the IP address of eth0 and wlan0. So Usually the eth0 will obtain an IP address by the ...
1
vote
2answers
49 views

Why does nmap remotely show when I have port 6969 open, but not others?

Specifically, I was running a node.js application on port 6969 which I thought was strictly local. I discovered this was not the case when I ran nmap <myip> from a different computer and found ...
5
votes
1answer
47 views

Safely Experimenting With Sockets

I'm learning about TCP/IP and (Berkeley/UNIX) socket programming. Let's say I have two scenarios: 1) I write two programs in C, a client and a server, and bind them each to a non-well-known port on ...
6
votes
1answer
64 views

Exploring unknown service

I'm fairly new to network stuff and currently exploring a Wi-Fi radio device in my home network. In this process I noticed an open port. 58028/tcp open unknown 1 service unrecognized despite ...
-3
votes
1answer
43 views

Little bit confusing with nmap scan

I started MySQL with this command service mysql start and it worked pretty well. So: Using the netstat command, I found 127.0.0.1:3306 was in listening state, this is the MySQL service. So I did a ...
0
votes
2answers
40 views

How do I scan my Routers Ports? [duplicate]

I recently scanned ports from within my LAN, but I recently read in order to determine whether Ports are open to the WAN I need to scan from outside the LAN, how do I do this?
0
votes
1answer
34 views

Resuming an interrupted nmap scan:

I need to: --resume <filename>: Resume an aborted interrupted scan. But I didn’t: -oN/-oX/-oS/-oG <file>: Output scan in normal, XML, s|<rIpt kIddi3, ...
2
votes
1answer
49 views

Static MAC address on Switches and routers

I was having a discussion with a friend of mine in IS industry and he insisted that setting static MAC addresses (i.e. port security) on devices were a effective way to block MAC spoofing. I found ...
-1
votes
2answers
92 views

How to limit source port for accessing blocked website?

My country has a firewall which blocks sites like Facebook, whatsApp etc. However, they use some kind of port blocking, so some important websites for me like Chegg is also getting blocked I think due ...
1
vote
1answer
53 views

FIN Scan: sneak through certain non-stateful firewalls?

Many resources stated that FIN scan can bypass non-stateful firewall: In Nmap document: The key advantage to these scan types is that they can sneak through certain non-stateful firewalls and ...
0
votes
1answer
86 views

What attacks or exploits are possible when MAC address, IP, and Port of a WiFi access point are known? [closed]

I just accepted a position at a small firm and was testing the previous WiFi setup for flaws and exploits that were possible. We have two AP's for business and guest connections, everything checks out ...
1
vote
2answers
43 views

nmap output to file different than interactive output?

I am running a simple SYN scan of all ports on all hosts that I found on a previous ping scan saved to a file: targets like this: nmap -sS -p- -v -T5 -oN puzzling.txt -iL targets As the scan runs ...
-1
votes
1answer
85 views

Unable to open port on Windows 7 [closed]

The scenario is as follows: while a PC was connected to our company's network, a specific application was able to open another process on a predefined port. It worked as expected. But now, this PC ...
3
votes
1answer
133 views

Common attacks when no ports are open

If you have a web server with all ports closed (except, of course, the necessary HTTP) what kind of attacks can an attacker use to hack into the system? Are the only vulnerabilities stuff like ...
2
votes
2answers
347 views

Telnet port open on my router public IPv6 address

Recently I upgraded my home router into this one. It is a cheap one, but it has features I needed: IPv6 support and Gigabit Ethernet. So I decided to give IPv6 a try. I configured a Hurricane ...
2
votes
1answer
72 views

Opening remote MySQL database to office IP address at default MySQL port risks?

I read a few questions regarding this topic that were pretty informative, but still wanted to pose my particular case. My company wants to put our data in the MySQL tables we have through our web ...
2
votes
1answer
131 views

Can the windows Remote Procedure Call subsystem be modified from the default without causing Windows 8/8.1/10 to break?

This is a question that personally as a security professional has bugged me for a long time. So, a default Windows installation, from XP up to 10, typically has a few services listening on the ...
1
vote
3answers
144 views

Does NAT really provide security? [duplicate]

I had an argument with someone on IRC about Network Address Translation. I was under the impression that NAT provided a layer of security to internal networks. I understand that's not the primary ...
0
votes
2answers
248 views

Does having these ports open indicate any vulnerabilities?

I installed Ubuntu Gnome a couple of weeks ago along with a few packages and some software. When I scanned my localhost using Nmap, I got the following results. Are there any obvious vulnerabilities, ...
0
votes
1answer
54 views

Security concerns with opening ports [duplicate]

New to network security here. Is exploiting known/zero day vulnerabilities on "listening" services after scanning for open ports the only way or at least the most common way to compromise a system? ...
3
votes
2answers
414 views

Scanning multiple subnets with nmap to determine open services & ports

First off, I know nmap's documentation is very powerful and I have been reading through it rather extensively. I will be scanning externally, with permission, to determine ports & services that ...
0
votes
2answers
85 views

Client misunderstanding nmap [closed]

My client wants their public facing IP addresses to be secure, but thinks that running nmap port scans will draw attention from hackers. To settle this once and for all, what do you say?
0
votes
0answers
23 views

Firewall issues

Background I have an Android device (Minix M5) that I handed to a customer The device only does outbound connections, so no inbound traffic The customer confirmed that s/he opened up the ports ...
2
votes
1answer
94 views

explanation of an nmap behaviour

I'm testing some vulnerabilities on a machine which has the port 22333 opened (it's used as the ssh port, and I can connect to it without any problem and the telned command get connected): $ telnet ...
-4
votes
1answer
81 views

how can the hacker benefit from the information of checking tcp port or udp port? [closed]

I studying a scanning and I want to ask how can the hacker benefit from the information of checking tcp port or udp port?
1
vote
1answer
58 views

Port forwarding with VPN

EDIT: My VPN has port forwarded a 5-digit tcp/udp port for me. What kind of attacks am I opening the computer to with VPN port forwarding?
-5
votes
2answers
1k views

What's the risk of opening ports 1-65535? [closed]

Just going to say this right now; this seems absolutely ludicrous. I've had a problem with playing Super Smash Bros. on Wii U ("Cannot connect to partner's device."; also happens for all ...
0
votes
1answer
240 views

Why is Parallels Plesk running on port 8443 > 1023?

Parallels Plesk, a server administration software package, uses HTTP(S) on port 8443 (ref). I know that ports <1024 are only available for root. This means that if the server Plesk is using for ...
1
vote
2answers
203 views

How do I check for inside-out open port? [closed]

I'm inside a corporate network and I want to assess which ports are open for outbound connection. There are such tools that do this test? I remember that years ago I used a website which performed ...
0
votes
1answer
243 views

Source port and destination port [closed]

Just fiddling with wireshark and telegram as part of some learning exercise on security. I realised that the source port for the telegram app is 58939 and the destination port would be 443. Why is ...
4
votes
1answer
598 views

Firewalk through a Firewall on our subnet

Having trouble firewalking. I am trying to determine all the open ports on my firewall/gateway. Here is my lab network diagram: (Skip to the bottom of the following explanation for a direct list of ...
0
votes
2answers
489 views

Opening port 53 on server Risks?

I looked about but couldn't find a similar enough question. I have some remote servers positioned on clients networks, which provide various services (raspberry pi) - and their firewall config is as ...
1
vote
1answer
374 views

nmap not running as root shows unknown open ports for a fraction of a second

On a server running Ubuntu 14.04.2 I was doing some basic security auditing when I ran the command nmap -p -d 1-65535 as a non-root user. Interestingly it reported a few (1-5 at a time, average, ...
5
votes
2answers
909 views

Why would a stealth scan attract more attention than a connect scan?

I'm reading an Information Security book and am faced with the question: Why may nmap stealth scans(SYN) attract more attention than simple connect scans(TCP connect())? Why might it be?
1
vote
0answers
194 views

open ports on a netgear N-150 router; disable SPI firewall? [closed]

How do I open all ports? At least internally, for LAN traffic from 192.168.1.x to 192.168.1.x I want all ports open. Even if it creates a security problem. thufir@doge:~$ thufir@doge:~$ nmap -p ...
1
vote
2answers
125 views

Mitigating DDoS With Command of Ports

Is there any type of DDoS where closing or taking full control of all port capabilities would be useful in mitigation of an attack?
2
votes
1answer
3k views

Security risk of opening port 111 (rpcbind)?

As far as I understood rpcbind is used for listing active services, and telling the requesting client where to send the RPC request. If a host listens on port 111, one can use rpcinfo to get program ...
2
votes
1answer
325 views

What is the fastest way to scan all ports of a single machine

I am doing some research and I need a very quick way to scan for open ports on a single machine. To provide some context, I know that my machine will have a port open waiting for UDP packets for about ...
-4
votes
1answer
108 views

How am I affected by malware? Malware transferred from service provider's base station or just port scan? [closed]

I need a malware expert here. I am being targeted by advanced hackers over the 4.5 years. So this is my situation: 1) My new phone: I just bought a new phone, with SIM card and mobile internet plan ...
10
votes
1answer
7k views

GHOST: which services are vulnerable, ssh, web server?

GHOST (CVE-2015-0235) just popped up. GHOST bug: is there a simple way to test if my system is secure? deals with how to find out if your system is vulnerable. exim is mentioned specifically. ...
13
votes
2answers
2k views

What's the diff between blocking a port with a firewall and not starting a service on that port in the first place?

I was considering setting up a software firewall (pf) on my web server and did some research on them. Were I to do it, it'd involve basically blocking connections to all ports except 80, 443, and the ...
3
votes
4answers
2k views

Is there a nmap command to get the top # most common ports?

I understand nmap by default scans the top 1k 'most common' ports (-F reduces to 100) I understand it gets these 'most common' ports based on the nmap-services file, specifically the frequency (3rd ...
2
votes
1answer
244 views

Understanding nmap output / author explanation …(Scapy)

I just read this example and explanation (below) in the OReilly book Security Power Tools (2007) in section 6.3 that is written by the creator of Scapy, Philippe Biondi. I think the example is very ...
2
votes
1answer
553 views

Firewall and Torrent

I use my university internet network and all incoming connection is blocked on every port.(they use netasq firewall) They have no other restrictions which stops me from using a torrent client. Using ...
2
votes
1answer
644 views

Why is nmap that slow on my system (ubuntu 14.04)?

I just started to learn something about portscanning with nmap. when i try to run an a nullscan or any other type on a virtual machine (win7 no firewall) the scan needs a lot of time to perform: ...
33
votes
4answers
13k views

Is there any meaning in only allowing port 80 and 443 today?

It's become standard fare for security minded organisations to block everything other than 80 and 443. As a result, more and more applications (other than web browsers) are learning to use these ports ...