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

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2answers
33 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
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1answer
65 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 ...
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1answer
24 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
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2answers
53 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
48 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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2answers
150 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
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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 ...
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2answers
73 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
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1answer
76 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
114 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
votes
1answer
124 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 ...
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3answers
81 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
142 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
1k 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
vote
3answers
681 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
88 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
107 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
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1answer
206 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 ...
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1answer
172 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?
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3answers
451 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
350 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
720 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
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3answers
417 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
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5answers
1k 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
128 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
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2answers
793 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?
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1answer
90 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
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1answer
99 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
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1answer
141 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
133 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
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1answer
65 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
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2answers
67 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 ...
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4answers
1k 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 ...
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1answer
510 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 ...
7
votes
2answers
5k 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
171 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
369 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 ...
2
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1answer
497 views

Why are some ports reported as closed by nmap?

I was scanning a machine from inside the same LAN which is running and up to date Windows XP Home Edition which I suspect may be running some malware. The target machine has an up to date antivirus ...
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2answers
526 views

Vulnerability of the open port

I'm installing service on the cloud machine and I was wondering on port vulnerabilities for my customers. My service which lives on server A (often on a customer site) needs to access server B ...
-1
votes
1answer
862 views

How to find IP Addresses that have been attacking my Computer Ports ? [closed]

I am a newbie at Info Sec, and wanted to know which IP addresses are sources of attack traffic. Can I also find out which ports are being attacked? Can this information be found in windows firewall? ...
2
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0answers
48 views

Could you attack a port without knowing what service was listening? [duplicate]

A lot of discussion I see suggests that changing default ports for services is just "security by obscurity" and is easily defeated by scanning for open ports. My question is this, though, if the ...
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1answer
1k views

Vulnerability by leaving an open port in a pc

I have the following set-up. Home pc ---reverse ssh tunnel---> to linux server The reverse ssh tunnel is set-up so that on my home pc, port 22 is open, but I have nothing currently listening on that ...
-4
votes
1answer
1k views

DoSing my Home Network with only a Public IP address [closed]

+--------------------------------------------------------+ | Client Host Name |.. IP Address ..|.... MAC Address ...| | Desktop-Home ....| 192.168.1.100 | 00:19:D1:EA:03:68 | | GT-S5380K ...
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4answers
522 views

SYN scan victim sending back RST

I'm confused on the case of SYN scan and closed ports (the case of open ports makes sense). So, the attacker sends a ~40 byte SYN packet, a "closed port" would send a RST packet back to the attacker ...
-1
votes
2answers
427 views

Keyloggers and Email Accounts [duplicate]

This morning, I was experimenting with some keyloggers and noticed that they have a feature to send e-mails to the attacker. How can these e-mails be intercepted? Let us say that I have a packet ...
0
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1answer
775 views

What are the ports used by Online Email Accounts such as Yahoo Mail, Gmail, etc.?

Let us say that I send an email using Yahoo Mail or GMail. Can this email be intercepted using a packet sniffer? On which port does the email travel? HTTP, SMTP, POP3?
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5answers
898 views

How to bypass Nmap blockage?

I rent a server, and my provider seems to be blocking nmap. Is there any other tools I could use to test my home network from the outside? Also, does blocking nmap on a network provide any security? ...
1
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2answers
387 views

Spike in TCP port 5904 activity - what for?

There is an 'Internet Weather Report' on the Threat!Traq video blog by AT&T security researchers. In the March 14th broadcast, at around 31 minutes in, they mention an increase of scanning ...
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3answers
446 views

How can i reject connection from LAN and WAN to some ports?

Scanning with nmap, I discovered that there are 3 open ports on my server. I want to deny any access to these ports from any machine, regardless of whether it is on the same LAN or via WAN. How do I ...
2
votes
2answers
4k views

How to configure iptables for must open ports?

On my machine there are web services which can be accessed from any PC connected to the same network segment (WiFi for example). I want to use IPtables on the machine to prevent any web services from ...