Network Security - securing network infrastructure and connections

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120
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8answers
13k 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 ...
86
votes
8answers
9k 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 ...
82
votes
7answers
81k 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?
58
votes
2answers
49k 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). ...
50
votes
6answers
18k 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 ...
44
votes
1answer
3k 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 ...
43
votes
9answers
21k 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 ...
42
votes
5answers
6k 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 ...
39
votes
4answers
5k 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
1answer
190k 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 ...
36
votes
9answers
42k 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 ...
33
votes
4answers
5k views

Why does malware periodically check google.com

I'm looking at some malware PCAPs, e.g. http://malware-traffic-analysis.net/2014/05/27/index.html . One of the things I've been seeing frequently is requests to alexa top million sites (e.g. yandex, ...
33
votes
7answers
34k 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 ...
33
votes
3answers
9k 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 ...
32
votes
7answers
52k 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 ...
32
votes
4answers
8k 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 ...
31
votes
3answers
13k views

How do you stop a hacker when their IP address is 0.0.0.0?

Wordfence reports the following visitor: An unknown location at IP 0.0.0.0 visited 4 hours 45 mins ago IP: 0.0.0.0 Browser: Baiduspider version 2.0 Mozilla/5.0 (compatible; Baiduspider/2.0; ...
31
votes
9answers
75k 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 ...
30
votes
10answers
28k 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 ...
30
votes
6answers
5k views

Can malware be dangerous even when quarantined?

I am reading a book on network security and when talking about user confusion it writes: "It is not uncommon for a user to be asked security questions such as Is it safe to quarantine this ...
30
votes
6answers
133k views

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

I have two questions on wifi security: If someone knows my wifi password (be it WEP or WPA) what can they see on my screen? Do they just see URLs I visit, or can they see everything in my ...
29
votes
4answers
28k 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 ...
28
votes
7answers
4k views

Is having Steam installed a security risk?

Speaking to one of our security administrators at work, he insists that Steam is a well understood security risk and it shouldn't be installed on work machines. Saying it's not work related I ...
28
votes
2answers
3k 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 ...
27
votes
3answers
4k views

Does Skype technology tap a user's machine to route other calls? [closed]

I was surfing a random blog today (Enterprise video conferencing solutions vs Skype), and I came across a claim. I do know that the Skype protocol is a proprietary one, but the author of this blog ...
26
votes
7answers
6k 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 ...
25
votes
3answers
925 views

What are the security risks in enabling ipv6

We are considering enabling ipv6 on our webservers, so that we are reachable with both ipv4 and ipv6. Are there any security issues we should consider when enabling ipv6?
24
votes
6answers
24k 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 ...
24
votes
2answers
79k 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?) ...
24
votes
5answers
4k 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 ...
23
votes
5answers
34k views

Is it still unsafe to email credit card number nowadays?

We all know not to do it, but someone emailed my credit card number and cvv code to my gmail. I'm wondering if the risk is so low I don't have to call to cancel my card. The email is sent from a ...
23
votes
3answers
5k views

How do DoS/DDoS work?

In the last days one could frequently read about attacks from anonymous and LulzSec against different platforms like Sony or HBGary etc. Yesterday for example they DDoS'ed soca.gov.uk and jhw.gov.cn. ...
23
votes
3answers
2k views

How does Convergence (CA replacement) prevent its notaries from being MITM'd as well?

I have been looking into Convergence and how it works, but I cant figure out how it is effective against a MITM attack that happens near the target system. My understanding is that Convergence works ...
23
votes
3answers
11k views

What benefits does Nessus have over OpenVAS?

Nessus and OpenVAS appear to have fairly similar features. Why would you choose one over the other, besides the benefit of commercial support (which isn't available for Nessus Home Feed users ...
22
votes
6answers
2k views

How to secure a WiFi network?

What do I have to do to secure a WiFi network? Is there any best practices? I have been recommended to use WPA2 encryption on the router, is that enough? What can I do to improve the security even ...
22
votes
2answers
2k views

How does this HTML5-based “Mass Router Infection” scheme work?

I read this article stating that purely through a website, "without any user interaction" mass router infection is (/was?) possible. I'm not sure that this problem still exists as it was posted 3 ...
22
votes
4answers
6k views

Are popular porn sites more likely to be infected with malware?

I'm trying to help my friend understand this because he believes that since a site is very popular, that it's less likely to infect its viewers because of its security! Is a popular site less likely ...
21
votes
8answers
5k views

Is there a way to make a WEP-secured AP uncrackable?

For some days, I was feeling that my Internet bill was booming. Then, I recently found out that a boy near my house was accessing my router to use the Internet. Then, I read some articles how to crack ...
21
votes
12answers
39k views

Public DMZ network architecture

Years ago, when I was a student, a network security professor taught me in a class what a DMZ is. The architecture he used in his slides was similar to this one: Now that I got employed, my boss, a ...
21
votes
8answers
4k views

Is possible to get infected by only staying connected to the Internet (nothing else)?

I have a router and I'm the only user. I have a computer with Linux and a tablet with Windows 8.1. Because of a few problems, I had to reinstall Windows on the tablet. Since I'm a bit paranoid about ...
21
votes
7answers
1k views

Securing the security guy's home office: what should we do?

I read an article in the latest InfoSecurity magazine (an infosec trade rag by Elsevier) saying that us security professionals aren't necessarily taking the correct steps to protect our own home ...
21
votes
1answer
6k views

What are darknets, and how can they be used to provide security and anonymity in network communication?

One of the major problems with the internet is that it's difficult to stay anonymous while retaining the ability to communicate with a large number of people. While encryption can be done effectively ...
20
votes
5answers
2k views

419 Nigerian scam problem

I fell in a scamming trap. It took me a while to figure it out. Blinded like an idiot. But it is what it is. I can only do as much as I can now. Tell me if there is anything else I should do. After ...
20
votes
5answers
20k 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 ...
19
votes
5answers
22k views

How to find out that a NIC is in promiscuous mode on a LAN?

How to find out that a NIC is in promiscuous mode on a LAN?
19
votes
9answers
4k views

Can IP address be a component of 2-factor authentication?

I have a bunch of Linux machines that I wish to administer over the Internet. I currently use SSH keys, but have been advised to use 2-factor authentication. SSH Keys are something you know. Is an IP ...
18
votes
3answers
1k views

Are open wireless networks unencrypted?

When you connect to an open wireless network (that is, a wireless network without any symmetric password set) is there any sort of secure key exchange going on, or is data sent back and forth ...
18
votes
4answers
11k views

Can home routers get infected?

I am behind a router(linksys that runs dd wrt on it) and I was infected with sality. I'm curious, can my router get infected too? If yes, how can I remove the infection? I used the search bar but ...
18
votes
5answers
9k views

Do you detect/react to DNS tunnelling?

I've just seen a talk about tunnelling TCP/IP over DNS requests, because port 53 UDP is usually open and unfiltered. What techniques exist to detect and block such tunnels, and have you ever seen that ...
18
votes
5answers
3k views

To firewall or not to firewall?

There's recently been some discussion (to be generous) about the pros and cons of having a firewall deployed in front of servers. The con mainly being that it's a point of failure in case of a DDoS. ...