Questions tagged [network]

Security of network infrastructure and network traffic. For questions about security of network equipment, topology, protocols, traffic, administration, and configuration. Related tags: [packet], [firewall], [network-scanners], [network-access-control].

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209
votes
8answers
187k views

What is the difference between SSL vs SSH? Which is more secure?

What is the difference between SSH and SSL? Which one is more secure, if you can compare them together? Which has more potential vulnerabilities?
136
votes
8answers
21k views

Are “man in the middle” attacks extremely rare?

In "Some thoughts on the iPhone contact list controversy and app security", cdixon blog Chris Dixon makes a statement about web security Many commentators have suggested that a primary security ...
120
votes
11answers
327k views

Can my employer see what I do on the internet when I am connected to the company network?

This is an attempt at a canonical question following this discussion on Meta. The aim is to produce basic answers that can be understood by the general audience. Let's say I browse the web and use ...
119
votes
12answers
23k views

Is there a legitimate reason I should be required to use my company's computer? (BYOD prohibited)

I just got a new job at a medium-sized (~100 employees) company and one of the first things I was told is that I cannot use my own computer, because I need to be able to connect to their network, ...
112
votes
15answers
43k views

How can mom monitor my internet history from a distance?

This might sound like a funny question from a twelve-year-old. The less funny part is that I am 21 and currently studying at university (I don't live at University, although I am 15 minutes away. I do ...
98
votes
4answers
154k views

Is it a bad idea for a firewall to block ICMP?

This question was inspired by this answer which states in part: The generic firewall manifest file finishes off by dropping everything I didn't otherwise allow (besides ICMP. Don't turn off ICMP). ...
95
votes
8answers
18k views

How can I protect my internet-connected devices from discovery by Shodan?

There's been a lot of buzz around this recent CNN article about Shodan, a search engine that can find and allow access to unsecured internet-connected devices. Shodan runs 24/7 and collects ...
95
votes
12answers
32k views

Landlord will be watching my data traffic, as mentioned in the lease agreement

I am moving to Germany, and in the contract I signed I had to accept that all my data traffic can/will be checked by the apartment owner. The contract states: Flatrate, aber hinter 30GB Tarif ...
89
votes
5answers
95k views

Should SSL be terminated at a load balancer?

When hosting a cluster of web application servers it’s common to have a reverse proxy (HAProxy, Nginx, F5, etc.) in between the cluster and the public internet to load balance traffic among app ...
81
votes
7answers
16k views

Company claims hardwire connections are a security issue

Someone to whom I am related is at a study camp for their desired profession. This person, let's call her Jane, is supposed to be studying rigorously for two months. The housing provided offers ...
81
votes
10answers
107k views

Why do people tell me not to use VLANs for security?

I have a network, where a have a couple of VLANS. There is a firewall between the 2 VLANs. I am using HP Procurve switches and have made sure that switch-to-switch links accept tagged frames only and ...
79
votes
8answers
19k views

Is it possible to “fake” being connected to a router?

A friend of mine is taking a UNIX systems class and mentioned to me that when they take exams they do so on their computers. That is all students are using their own computer/laptop. Students are not ...
78
votes
8answers
27k views

How is no password more secure than username+password?

Context: I have a laptop supplied by my organisation. I am trying to connect to eduroam, but I cannot do it using my organisation's laptop. When I use a personal computer, it asks me for a username ...
78
votes
1answer
9k views

What is this kind of low-intensity, non-hacking attack on a web service?

I am seeing for about 10 days now a bunch of EC2 machines (about 30, distributed in all regions) which are attacking a server of mine. The interesting (or uninteresting, I do not know yet) fact is ...
76
votes
9answers
20k views

Is it theoretically possible to deploy backdoors on ports higher than 65535?

Assuming you were able to modify the OS/firmware/device for server/client to send and listen on ports higher than 65535, could it be possible to plant a backdoor and have it listen on, say, port 70000?...
74
votes
5answers
35k views

What techniques do advanced firewalls use to protect againt DoS/DDoS?

It is hard to protect a server against Denial of Service attacks, DoS/DDoS. The two simple ways I can think of is to use a server with much resources (e.g. CPU and memory), and to build the server ...
68
votes
5answers
18k views

Is a 'dumbphone' mobile more secure for basic phone calls than a smartphone?

By dumbphone I mean: no internet connection, very limited features, etc. By more secure I mean: secure from malicious and direct hacking. I don't mean as in protected from government tapping/snooping;...
66
votes
8answers
51k views

Are powerline ethernet adapters inherently secure?

I have 2 Zyxel PLA407 powerline adapters. Router is downstairs connected to one adapter, other adapter is upstairs about 30 feet away connected to a desktop. I have a house, not an apartment or ...
65
votes
4answers
7k views

Why should servers be placed outside of the corporate network?

In an answer to How do you deal with massive port scans?, user tylerl said: ... And you, like a wise IT admin, run all your servers elsewhere on the internet, not inside your corp network, for a ...
65
votes
1answer
5k views

What's the risk if I accidently type my password into a username field (Windows logon)?

I'm used to logging into my personal Mac which is a password-only field (like waking from sleep mode). Sometimes I have to use a Windows network on which I have an account, but of course I have to ...
64
votes
8answers
118k views

What is the difference in security between a VPN- and a SSL-connection?

I would like to design a client-server application where the server is placed on Internet. I assume that I could set up the client-server connection using VPN (is it using IPSec?) or using a SSL ...
63
votes
9answers
125k views

How secure is TeamViewer for simple remote support?

I'm deploying a web-based ERP system for a customer, such that both the server and the client machines will be inside the customer's intranet. I was advised in another question not to use TeamViewer ...
62
votes
6answers
421k views

If someone hacks my wi-fi password, what can they see and how?

If someone knows my wifi password (be it WEP or WPA) what can they see? Do they just see URLs I visit, or can they see everything in my browser, or even everything I do on my computer? Does using ...
59
votes
10answers
115k views

Why block outgoing network traffic with a firewall?

In terms of a home network, is there any reason to set up a router firewall so that all outgoing ports are blocked, and then open specific ports for things such as HTTP, HTTPS, etc. Given that every ...
59
votes
3answers
15k views

Does your ISP know what type of phone/computer you're using?

For instance do they know whether you're using an iPhone or Samsung?
57
votes
3answers
7k views

Is it common practice for companies to MITM HTTPS traffic?

My company has just introduced a new VPN policy whereby once connected all traffic is routed the company network. This is to allow for improved monitoring of data theft. It would appear that this ...
56
votes
10answers
11k views

Does the local network need to be hacked first for IoT devices to be accessible?

I completely understand how IoT devices were used in the massive DDoS attacks because they are easily manipulated due to lack of firewalls, default passwords, etc. What I don't understand is although ...
55
votes
13answers
9k views

Is it dangerous to use default router admin passwords if only trusted users are allowed on the network?

There are a lot of articles addressing the dangers of default router admin passwords. Certain security applications will also detect default router admin passwords as a vulnerability. However, these ...
55
votes
7answers
9k views

Can you hide a server's existence on the internet?

Would it possible to appear as though a server doesn't exist? Is it possible to have all requests believe host-name could not be resolved unless a specific phrase was provided in the request? Is there ...
54
votes
3answers
257k views

What is the real function and use of a DMZ on a network?

I read the article on Wikipedia describing what a DMZ (demilitarized zone) is on a network, but am still failing to grasp both how it is set up (ie: is it within the main network or sequestered away?) ...
50
votes
7answers
56k views

With IPv6 do we need to use NAT any more?

I'm wondering how to use NAT with IPv6. Seems that you don't even need it any more. So what exactly is the concept behind firewall configurations in IPv6 environments?
50
votes
1answer
245k views

Why can you bypass restricted WiFis by adding “?.jpg” to the URL?

I recently read an article on Hacking a commercial airport WLAN. It's basically about circumventing paid airport WiFi redirections (they redirect you to a certain URL when you type something in the ...
48
votes
5answers
9k views

Bring your own phone to a (new) job: Consequences?

I am starting a new job, and I have the choice to receive a phone from the company, or to bring my own. I am considering using my own phone, to avoid having an extra device, but I want to better ...
47
votes
13answers
42k views

DDoS - Impossible to stop?

Is it possible - in theory - to stop1 a DDoS attack of any size? Many people claim it's impossible to stop DDoS attacks and tell me I just shouldn't mess with the wrong people on the internet. But ...
47
votes
4answers
9k views

Do simple Linux servers really need a non-root user for security reasons?

Playing devil's advocate, Let's assume I purchase a Linux server from a hosting provider. I am given a password for the root user and am told I may login using SSH. The only purpose this server has ...
47
votes
2answers
2k views

WPA2 ephemeral key derivation

I'm trying to learn how ephemeral keys in WPA2 4-way handshake are derived. Starting from 4 EAPOL packets sniffing, I successfully derived PMK and PTK reading ANonce, SNonce, and knowing ASCII-PSK ...
45
votes
12answers
8k views

Would it be more secure or not if all computers in the network use the same operating system?

If all the computers use the same operating system, attackers only need to focus on one operating system, would it be unsafe?
45
votes
6answers
60k views

Security risk of PING?

I have been told that PING presents a security risk, and it's a good idea to disable/block it on production web servers. Some research tells me that there are indeed security risks. Is it common ...
43
votes
3answers
49k views

What is the best home wireless network encryption algorithm to use?

What is the best home wireless network encryption algorithm to use? I realize the best answer will probably change over time, and hopefully people can provide updated answers as new standards come ...
41
votes
5answers
35k views

My WiFi network is replaced by another network. Am I being hacked?

To begin with, I am not very computer savvy. I am an older person with an older computer and a 2003 Windows XP using Google Chrome for a browser. (If anyone is old enough to remember when Windows ...
41
votes
5answers
8k views

Is this an evidence of a Skype communication being spied on?

A couple of days ago I was having a conversation using Skype, then I wanted to share a link to a page with the interlocutor. I didn't want to let her understand the link content by just looking at the ...
40
votes
6answers
21k views

Why is external access to a server via SSH considered insecure?

I recently had a conversation with my boss and an IT contractor that they use. My request to allow outside access to a machine on the network via SSH was denied on the grounds that SSH is insecure. I ...
40
votes
7answers
14k views

Port Knocking is it a good idea?

Normally for a server I like to lock down SSH and other non-public service to only be accessible by certain IP addresses. However this is not always practical if the business doesn’t have static IP ...
40
votes
6answers
69k views

Can I detect a MITM attack?

Based on this question here: Are "man in the middle" attacks extremely rare? Is it possible to detect man-in-the-middle attacks, and if so, how would one go about it? In addition, what if ...
39
votes
4answers
7k views

Can a neighbour who installed my router access it?

I have a bit of a security concern. I'm concerned that my neighbor sees everything on my computer, web sites I have visited, my passwords, etc. Background: He installed a Linksys router in my house ...
38
votes
4answers
6k views

How can you change “system fonts” in Firefox (to increase own safety & privacy)?

I know there were some previous (similar) questions to this, I have read them all and also tried but nothing has really helped (maybe because it was outdated information). What I did was I went to: ...
37
votes
8answers
19k views

Unknown suspects hijacking our WiFi. Caught their MAC addresses [duplicate]

I noticed our Internet was bogged down. I checked the IP addresses of all devices connected and found the MAC addresses of the culprits: Question: How to find their geographical location based on ...
37
votes
5answers
8k views

Security impact of using a public password for free WiFi

We have a WiFi network that we want to be public and free. Does having a password that is known to everyone provide any additional security advantage to the people using this network as opposed to ...
36
votes
2answers
7k views

Is it safe to buy a router if its serial number and other details are exposed on the web?

I'm looking to buy a WiFi router on ebay, but the seller put a picture on the site of the router's backside, exposing information such as Serial number Part number MAC address Default password and ...
35
votes
4answers
35k 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 ...