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Questions tagged [ports]

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

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What am I missing in port forwarding? [migrated]

I am trying to forward a specific port on my router with listening to that port number, but when I run canyouseeme tool, it shows the connection is refused. I made the inbound rule, no firewall no ...
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7 views

Port Forwarding vs Port Triggering for online game Elder Scrolls Online [migrated]

My system is Windows 10 on a TP-Link WDR3600 router (no VPN). I use this computer for banking and other important things. I'm no network engineer but I've heard port forwarding puts you more at risk ...
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1answer
42 views

Is it safe to have port 443 unprotected by firewall without application?

Say I have a website, http://www.mostlysecuresite.com, which runs on a server at my house. Let's say I wanted to get an SSL cert in a few weeks. Because of this, I had my Port 443 forwarded on my ...
45
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5answers
13k views

Should I close port 80 forever and ever since the 2018 Google-indicated web-security initiatives?

I often establish Ubuntu-LAMP environments on which I host a few Drupal web applications that I myself own (I don't provide any hosting services and never done so in the past). Whenever I establish ...
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2answers
58 views

Port bound TLS certificates? (1 Self-signed & 1 CA)

For my android game, I want to secure the connection between the server and its clients through TLS certificates on each side, because of the sensitive data that is beeing exchanged through a token ...
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1answer
66 views

Understanding port scanning with firewall enabled

My objective is to do a port scanner in windows and find the ports which are open. Suppose, I run an application which opens up a port 8000. Now I create a new inbound rule to block all incoming ...
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2answers
102 views

Do I have to block UDP ports when I launch my own server with a public IP?

I am trying to give better security to my Raspberry sever. When I installed UFW, I allowed just port 80/tcp and my own high port for SSH communication, and by default are all others ports "deny". ...
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1answer
27 views

Why do processes on servers have socket types associated to the port number? [closed]

Why do some servers have TCP/UDP alongside the port they're listening to. To my understanding TCP and UDP are socket layers, they're methods of determining how the traffic is being sent over the ...
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1answer
140 views

NMAP reporting all ports open

I'm trying to scan my targets for open ports. However, NMAP reports all of them as 'open'. I know there's a firewall in between. I tried the SYN scan, and when I check the traffic in WireShark I see ...
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3answers
82 views

Nmap scanning single port too fast? Shows as filtered?

I ran into an issue when trying to scan a single port on a single machine. I ran a range scan to find machines with port 25 open. Then I just arbitrarily chose one to work on. I scan that machine with ...
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1answer
78 views

Port knocking is authentication?

In computer networking, port knocking is a method of externally opening ports on a firewall by generating a connection attempt on a set of prespecified closed ports. Once a correct sequence of ...
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1answer
34 views

What is an excessive amount of SYN requests for port scanning?

I have a slow internet connection - about 12Mb/s. In 10 minutes I have detected a distributed port scan on the router from different IPs. I have counted these SYN packets at in 600 seconds (10 minutes ...
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1answer
214 views

Why adclick.g.doubleclick.net listens on all ports [closed]

I have adclick.g.doubleclick.net listening on all ports. When I launch an application like Starcraft 2, for example, it is listening on localhost. Or for some applications, there was a connection from ...
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1answer
145 views

What are the possible solution for blocking VPN connection on a home network?

I am not a techie. I am just wanting to force some parentral control using OPENDNS. Opendns works fine however it is easily broken on android or windows using vpn software like ultrasurf or latern or ...
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2answers
43 views

Is there a point to set up passwords for services like MySQL, Redis etc. if we disable their related ports?

Redis' default port is 6379 and MySQL's default port is 3306. Let's say we disable these ports to outside of the world with ufw. And let's say only I have access to the servers. Is there still a point ...
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1answer
100 views

What ports can make me get RCE on the devices? [closed]

I know that remote code execution depends on the service running on the open port. For example I know that SSH, FTP may be vulnerable to RCE if they are running an unpatched version. So what about ...
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1answer
90 views

Does Windows perform TCP and/or UDP port scans? [closed]

I want to know whether Windows Operating System does TCP/UDP port scans, and how often if it does? Thanks for your time.
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1answer
81 views

Refusal to 'open' up corporate network?

I am working a project which requires access to a service running on a remote server, over a single TCP port (>1024). This service runs on a machine located within an existing network, and the project ...
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2answers
2k views

Can a hacker hack into port 80?

We normally say port 80 is firewall friendly. But can a hacker just hack into port 80 via TCP or UDP? Or is Port 80 by default not always open? It waits for the host to initiate a connection via ...
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3answers
926 views

Port sweep vs port scan

I was asked this question in an interview: "What is a port sweep?" When I replied with port scan he said that my answer was not a scan, it was a port sweep. I googled and found "tcp sweep: but not "...
2
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1answer
96 views

Port Knock logs suggest machine has been compromised?

On my CentOS machine, all my ports are filtered with the Iptables rule: DROP all -- * * 0.0.0.0/0 0.0.0.0/0 So from the Internet, every port timeouts. The only way to ...
3
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2answers
93 views

Nmap and it default scripts when I already know some of the information

I am a network guy and not a “hacker” or whatever the official term is these days. I’ve been learning how to use nmap as I think it’s a great tool for just keeping the network secure. The thing is ...
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2answers
271 views

Close Port 587 - Ramifications?

Our recent PCI scan failed because "Plaintext authentication is allowed over unencrypted channel on SMTP." As such, our tech support suggested to close port 587. What are the effects of closing port ...
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0answers
382 views

Using burp suite, how can I intercept traffic from one localhost port, but not another one

I have one webapp available on localhost:12345, and another service running on `localhost:6789'. I want to monitor the traffic to/from the webapp (12345), but universally pass the traffic to the ...
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2answers
348 views

Multiple Open ports on a server, is that safe? [closed]

Using nmap I try to scan a server as a result I get multiple open ports. For example when I try to scan domain.com as a result: 7/tcp open echo 9/tcp open discard 13/tcp open daytime 21/tcp filtered ...
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1answer
2k views

What are non-standard ports and protocols [closed]

I am new to the security field and reading about how to check if an application is secure. One of the checks involves finding out if the app uses non-standard security ports and protocols. However, ...
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1answer
756 views

How to use beef-xss on ports other than default 3000?

I want to use BeEF-XSS Framework over WAN (for educational purposes). The only problem is that my ISP is blocking port 3000. So, after some research, I found this page that says: However, beef-xss ...
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1answer
50 views

Opened port leads to a collection listing

I've been doing some searching on a macOS server and have noticed that there's an open port that I am able to access outside the network. When I go to this port it will ask for a username and a ...
4
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1answer
203 views

How to distinguish between “normal internet” Port scan and more “serious” port scan preparing attack?

In a complete network infrastructure, with firewalls, routers, servers supervised by a SIEM, LogPoint here. Of course, there is a private network and public servers. in the LogPoint there is an ...
7
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1answer
2k views

Connection to ports 2000 and 5060 successful despite filtering

I run my own (Ubuntu based) router and have iptables configured to drop all incoming packets by default. To my surprise, running an nmap scan (from the WAN side) shows two open ports related to VOIP: ...
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1answer
327 views

ufw and nmap show different result in terms of open ports

I have set my firewall ufw / firewall rules as follows: Default: deny (incoming), allow (outgoing), disabled (routed) To Action From -- ...
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0answers
42 views

Machine reaching out to Microsoft IP address using NBTstat command

I have limited logs for this event but the IPS says its a NBTstat query outbound over UDP port 137 to a Microsoft owned IP address. Should UDP 137 ever reach out externally? This is about all the ...
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2answers
244 views

My ISP blocks incoming ports so I can't even run webserver let alone 'reverse shell', any ideas? [closed]

I'm looking for ideas on how to run lab environment from "victim" test PC at work and "attacker" - my home PC. Both are on separate ISPs, but it seems that my ISP at home blocks anyone trying to ...
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2answers
933 views

Should I allow incoming traffic from source port 443?

I am hosting a web server, both standard and SSL. Both work fine currently. In my logs, I've noticed what seems like a distributed port-scan: 10-15 port queries from random hosts occuring within ...
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1answer
248 views

Replace Nmap with Nessus

I have to replace NMAP with Nessus. I got answer for few settings, but there are few settings in NMAP for which I am not able to get answer. If you could answer me, it would be helpful. For example, ...
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2answers
158 views

do SRV records make a system more vulnerable or expose too much

We are all pretty comfortable with the fact that if ports 80 and 443 are open that these are for http even though some companies block 22 forcing people to repurpose 443 for ssh. So, those instances ...
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3answers
3k views

Nessus Port scan Vs NMAP Port scan

My objective is to find network vulnerabilities. I have used Nessus and NMAP both for vulnerability scan. I have to verify if I can use only "Nessus" rather than using "NMAP". According to my ...
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2answers
5k views

How wise is it to use a tool for portspoofing at your server to confuse attackers?

I came across this tool recently https://github.com/drk1wi/portspoof How efficient will it be to use it to confuse hackers doing port scanning? If it's actually going to be pretty efficient, why ...
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2answers
2k views

Tons of vulnerabilities are found on tcp/0 port using vulnerability scanners

Performed credentialed Vulnerability scan on linux/Unix servers by Nessus and thousand of vulnerability came out of port tcp/0. How could a IANA reserved port(tcp/0) handle traffic? Are those ...
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1answer
71 views

Security of a Unity 2017 Cache Server

I am currently running a cache server on an ubuntu machine on our local network for an upcoming game. We have several off-site members of our team who would like to make use of the cache server too. ...
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3answers
183 views

Minimal usage in Windows 10 justify filtering all ports besides 22, 80, 443?

I use Windows 10 home on my personal computer. I opened up cmd and ran: netstat -a I saw a large list of ports that are on "LISTEN" mode and some others I couldn't recognize their state as I never ...
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1answer
42 views

Port filtering for Ubuntu-Nginx minimal server environment

I've established a minimal, uncustomized LEMP stack (Ubuntu 16.04). The only server I have besides Nginx is Postfix. To protect that environment I filtered all ports besides a few, this way: ufw ...
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2answers
249 views

Should I keep incoming data UDP ports open in a minimal server environment?

I have a minimal, uncustomized Ubuntu 16.04 xenial Nginx server environment with only these incoming data TCP ports unfiltered: 22, 80, 443, 9000 When reviewing /etc/csf/csf.conf I found out that ...
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2answers
1k views

Most efficient way to scan for webservers

Lets say I want to scan a large amount of ip addresses for webservers running on port 80 (aware that there are other ports for webservers, ignoring for example). What would be the most efficient way ...
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3answers
132 views

Can an attacker with MitM privileges perform denial of service and other attacks besides interception on local LAN?

I would like to better understand what an attacker who has MitM control on a LAN can do to the victim. I understand that basically a MitM attack means you intercept traffic and can see the data [and ...
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1answer
8k views

How can I check open ports on android? [closed]

I know that every ISO based network system uses TCP port, and Android is of course not an exception. My question is, can I check the open ports in my device? Can I close them? Is there an app to ...
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2answers
160 views

How can a computer found on traceroute show all ports closed?

I ran a traceroute on a website I'm connecting to and got the following output: 1 skyrouter (192.168.0.1) 3.989 ms 1.389 ms 1.916 ms 2 * * * 3 be397.pr2.thlon.isp.sky.com (2.120.11.8) 31.564 ...
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1answer
825 views

Port scans: 'traffic denied' VS 'close - age out'

I have been investigating logs from the firewall (Juniper) and I've found out that when someone is portscanning my website, the majority of the traffic through different tcp/udp ports is denied (...
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1answer
41 views

How to connect to external address as other outgoing port number without proxy [closed]

Is it possible to (mask / define) outgoing port locally on network without using a proxy? default (outgoing protocol) [address] [port] set to (outgoing protocol) [address] [selected port] There ...
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1answer
82 views

Why is it bad to open ports to ip cams? How does a VPN fix this?

I have been running a couple home web cams that I can view when away from home, by opening ports on my router. They are strongly password protected. An IPCam forum that I read says that you should ...