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

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1answer
73 views

Telnet Open, is this an exploit? [closed]

I am pentesting a server, and it appears my ports are open for telnet. Upon accessing telnet, if I type "help" I only get these commands: telnet> help Commands may be abbreviated. Commands are: ...
0
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1answer
51 views

Are these port secured on my AP?

I'm doing a project for my high-school and I'm trying to get the best security for my network. I've made almost everything in my access-point configuration and I have only 3 tcp/ports open on my AP: ...
2
votes
2answers
107 views

Protecting against GCHQ port scans: How does TCP stealth work?

Today I read the first time about a draft of TCP Stealth which should serve as a protection against GCHQ and NSA vulnerability scanning(Source: https://en.wikipedia.org/wiki/TCP_Stealth): The ...
7
votes
2answers
384 views

How nmap guesses the operating system?

nmap has the capability to guess the operating system with the option -O. I was highly surprised that it can find the correct kernel or service pack. * How nmap guesses the operating system? * What ...
0
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2answers
67 views

Impossible to make connections through closed ports?

If you have closed all your ports on your internet protocol, you cannot make a connection to that internet protocol. So how do attackers (DoS or any other means that need a connection) make a ...
3
votes
1answer
70 views

Internal IP addresses allowed access to all DMZ hosts

Hi basically I'm doing a vulnerability assessment for at the moment. The setup includes a DMZ with a single firewall and an internal network (3 legged network model employing a single DMZ) but on the ...
0
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2answers
99 views

Does Nmap requires a closed TCP port to do OS fingerprinting?

I was checking the security of a server by running Nmap. Last time it gives me the following results, indicating that OS could not be fingerprinted: PORT STATE SERVICE VERSION 21/tcp ...
2
votes
2answers
131 views

How common is port-knocking? [closed]

Today I read about port-knocking for the first time. It has been a pretty known concept for more than ten years, but I don't know anybody who uses it for their servers. How common is the usage of ...
0
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0answers
73 views

OSSEC, what is it telling me about port changes?

I've been diving into OSSEC for the last couple of months, but I feel unclear on one of it's alerts. I've provided the alert below. The main difference I see in previous output and current output is ...
0
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1answer
78 views

Detecting port scans in OSX kernel

Is it possible to detect port scans on OSX at the kernel level? I would like to write a kext that detects the ip addresses of systems scanning my computers ports. How exactly does a stealth scan ...
0
votes
1answer
55 views

Web browser initiating connection on non-standard ports. Should it be blocked?

I am doing some egress monitoring on my computer. Once in every few days, I would find some strange connections being logged, which I believe is initiated by the web browser through a related but not ...
1
vote
1answer
56 views

How to check whether firewall allows traffic on specific port but not listening on the port [closed]

I have client / server and there is a firewall between them.The server is listening on a port and I want to check if this port is allowed by the firewall. I can only know the ports that the machine ...
2
votes
2answers
818 views

I ran a netstat on my server and port 80 is listening, does that mean it is open and vulnerable to attacks? [closed]

Sorry I am just getting into Web Development and trying to learn more about servers and PHP, so I downloaded the LAMP stack on an Ubuntu14 OS and started an apache2 server. tcp6 0 0 :::80 ...
0
votes
2answers
44 views

Only allow access to specific service running on computer in Demilitarized Zone over internet

If a computer (running different services such as ftp and ssh) is placed on a Demilitarized Zone, will all of its services automatically be accessed by anyone on the internet? If the answer is yes, ...
3
votes
1answer
75 views

Is it possible to find out what a remote user is trying to do connecting to a closed port?

From my iptables log, I can observe a particular remote IP address trying to connect to my server from port 80 to a private port number: Jul 09 01:24:41 example.com kernel: IPTABLES: IN=eth1 ...
0
votes
1answer
57 views

How to turn of telnet and FTP on Thomson 789vn router? [closed]

I have run a port scan against a Thomson 789vn router and have noticed to my surprise that its HTTP as well as telnet and FTP ports are open. How can one turn off telnet (also FTP) using the router's ...
0
votes
2answers
117 views

Nmap stealth scan shows that port is filtered

The title is really bad, but I was able to find better. I have installed Debian on VMware, and set iptables to block any traffic except port 80 (inbound and outbound). When I run a nmap scan it shows ...
0
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1answer
84 views

NMAP not reporting open ports with -sS scan

Is there any reason why an -sS scan (or most others) would not report an open port that doesn't have a service attached to it? For example, in a regular -sS scan, the following port will be missing, ...
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votes
2answers
2k views

VPN blocked ports problem

I use VPN quite often in public places where I don't want anyone to read my web traffic. However, some public places have firewalls that block ports required to establish a VPN connection (I usually ...
3
votes
2answers
1k views

Is my ISP doing a port scan on my computer?

I have been logging incoming connections with iptables for a while and I have been observing the following popping up periodically: 11:45:10 my.com kernel: IPTABLES: SRC=220.255.XX.XXY ...
0
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2answers
135 views

Creating port-specific SSH authentication for the same user

I have a Linux server running SSHD and would like to know if its possible to configure it, such that from within the LAN you only need a RSA key to authenticate (on port X), but from outside the LAN ...
0
votes
1answer
269 views

MAC-address restricted port forwarding

I have an ASUS RT-AC68U router and would like to set up port forwarding, but I would like to restrict which MAC addresses can connect through that port. My use case is that I'll have a live camera, ...
0
votes
1answer
141 views

Finding the firewall port that filters internet traffic [closed]

In my office, we have static IP's for each system. All the internet traffic from our systems are filtered with a Fortiguard firewall. Is it the default gateway where the firewall is installed? How can ...
0
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1answer
196 views

Outbound Port 443 Open but Not Allowing SSH [closed]

My college wireless network has a firewall blocking all outbound ports except 443 and 80. The wired network, however, has none of these restrictions. I can connect to HTTPS sites (obviously). On my ...
1
vote
3answers
96 views

Is forwarding a port(s) a security risk to all computers on the network or just one?

I know forwarding ports can add some security risk, but if I forward a port to a computer, say running linux, would it add a security risk to all computers on my network or just the one?
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2answers
196 views

What security does an ISP provide for its customers?

I've heard that ISPs provide some kind of protection; using NAT and firewalls, to prevent hackers from using tools such as nmap to attack customers from over the Internet. What other technologies are ...
3
votes
1answer
2k views

Setup of Kali Linux for reverse shell connections over the internet

I am running Kali Linux as a VM on my Windows machine which is NAT'd behind my company network, if I wish to pen test a website for a client and believe that a reverse shell is possible, what is a ...
1
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3answers
2k views

Exploiting through a filtered port

I'm doing some pentesting against a machine the lecturer set up in the lab. NMAP shows port 445 to be filtered and Nessus confirms the ms08_067 vulnerability is present on that machine. I tried ...
0
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1answer
117 views

Is there a way of determining if tor is running on a remote machine?

In most of the companies, IT guys block some sites and by using TOR or other VPNs people walk around these blocks and gain access to blocked content. My question is, assuming TOR is running on ...
2
votes
1answer
157 views

What does Msgsrvr and Scientia-ssdb do?

I'm having a task in a computer security class in school where I'm supposed to scan a host for open ports in order to find out what services is being run there. I have found out (among other things) ...
1
vote
1answer
473 views

Does connection that use 0.0.0.0 in Foreign Address secured?

When I run my application on Centos the specific process opens port that listens for connections from localhost, but uses 0.0.0.0 in Foreign Address. Is it secured? netstat -plunt Active Internet ...
0
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1answer
227 views

Can closing port 80 lead to more security?

If a website is running on HTTPS only, is it reasonable to close port 80 of the web server and only leave port 443 open? Does this action provide more security for the website?
1
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3answers
988 views

Why P2P need portforwarding when behind NAT? [closed]

Correct me if I'm wrong, but for a node to participate in peer-to-peer, if it's behind a NAT, it most port forward to be able to connect. Why is the port forwarding necessary? I know there's ...
0
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1answer
454 views

Netgear WNDR4000 open port 53

Why is port 53 open on the WAN side of the router? And more importantly how do I close it? Port 53 is not one of my forwarded ports. Discovered by doing nmap -pT:1-64 <my-external-IP> -Pn ...
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votes
2answers
1k views

Port list according to vulnerability [closed]

I'm looking for a list of ports sorted according to the number of vulnerability you can find for that specific port (considering of course, the service installed in the default port). Example: ...
2
votes
3answers
618 views

Why block network ports?

There was another good question here on why you should block outgoing traffic: Why block outgoing network traffic with a firewall? But I was hoping to get an answer on why it is a good idea to block ...
2
votes
5answers
2k views

Nmap reporting almost every port as open

I have noticed during some assesments when doing a TCP port scan, Nmap will report almost every port as open for a machine. Using for example nmap -sS -PN -T4 target -p0-65535, over 20,000 ports will ...
0
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1answer
174 views

Is it possible to scan a remote host in another network if I know a port that is opened?

First of all, this question is not the same as is it possible to test out remote host by using nmap?, because on that question, the questioner is asking for something impossible due to NAT's nature. ...
0
votes
2answers
2k views

Is Port Forwarding for bit torrent risky?

I have found that my connection decreased suddenly when downloading torrents. I diagnosed it with bit torrent and the answer is that i should do port forwarding on my modem/router! Is it risky?
1
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1answer
110 views

Hardening Services, Ports on OSX

People boast about OSX Security, yet I find it very hard to find a comprehensive manual in regards to any equivalent Services and the ports they use. I am aware of lanchd and launchctl and Lingon is ...
0
votes
1answer
111 views

Understanding a Zenmap output

I'm running Zenmap on my Windows 7 laptop. I ran an intense scan with UDP targeting my router 192.168.1.1.I realize that I'm probing into the back end of the router from the inside and that any open ...
0
votes
1answer
177 views

Open ports on mac. Safe?

My friend is currently running the default firewall on his mac with "Block all incoming connection" (except the basic ones like 80). I just scanned his mac for open ports and I found the following: ...
2
votes
2answers
151 views

Hide logging server from DMZ

I have a server on my DMZ whichs relays syslog and OcsInventory messages to a server on a vlan for logging servers. In order to allow the packets to go through I must allow port 80 (OcsInventory) and ...
0
votes
1answer
84 views

Security risks monitoring JMX

I am doing an internship at a big company wich create industrial automated systems for some big company's. They want me to design a way to monitor all the Java based control modules. Now I am going to ...
0
votes
2answers
80 views

Can I communicate with a wireless device, without logging in the same LAN?

Suppose there are three devices: WPA2 protected AP linux laptop, accessing internet through tha AP linux laptop, not connected to the AP I own the third device and do not know the AP's password. I ...
1
vote
4answers
2k views

How to make nmap list an unfiltered port?

I have a host that is NAT'ed and I have opened a single port in my router so the host is reachable by the external world. I tested if it was reachable by running a service and connecting to it ...
0
votes
1answer
683 views

In-office Flask app on port 80 - is it safe? [closed]

The title says it all; I'm just serving data to coworkers as a courtesy via a series of single-page apps that I basically consolidated under Flask, serving Jinja templates. Presently, I have Apache ...
8
votes
2answers
9k views

What are the security implications of enabling UPnP in my home router?

I found port forwarding entries in home router that I haven't manually configured. Is that because of UPnP? Are applications simply able to tell the router to forward ports on their own? Are there ...
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votes
3answers
189 views

What are ports? [closed]

I just wanted to know what are ports. Can someone explain to me what a port is?
7
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1answer
423 views

different portscan tools give different results

I have different results as of my open TCP ports. When using nmap -sS 127.0.0.1, I get some 5 usual open ports, but when using osx built-in tool as stroke, I get those 5 ports plus 5 extra ports. How ...