Network Security - securing network infrastructure and connections

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127
votes
7answers
109k 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?
126
votes
8answers
15k 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 ...
95
votes
12answers
19k 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, ...
95
votes
14answers
28k 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 ...
89
votes
8answers
12k 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 ...
70
votes
2answers
74k 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). ...
60
votes
6answers
24k 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 ...
60
votes
4answers
6k 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 ...
50
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 ...
48
votes
8answers
29k 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 ...
43
votes
9answers
97k 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 ...
43
votes
5answers
7k 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 ...
42
votes
3answers
4k 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 ...
42
votes
1answer
210k 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 ...
41
votes
9answers
50k 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 ...
40
votes
9answers
59k 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 ...
40
votes
5answers
6k 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 ...
39
votes
7answers
70k 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 ...
38
votes
4answers
6k 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 ...
37
votes
11answers
33k 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 ...
36
votes
3answers
23k 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 ...
36
votes
6answers
173k 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 ...
36
votes
0answers
860 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 ...
32
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, ...
32
votes
4answers
16k 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 ...
32
votes
4answers
41k 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 ...
32
votes
2answers
5k 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 ...
31
votes
3answers
14k 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; ...
30
votes
7answers
5k 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 ...
30
votes
6answers
6k 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 ...
29
votes
7answers
8k 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 ...
29
votes
3answers
5k 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 ...
29
votes
2answers
115k 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?) ...
27
votes
5answers
5k views

Advantages to killing sessions after 5 minutes?

I'm dealing with a server that isn't mine to configure. Something somewhere between me and this server kills any connection after 5 minutes if no traffic passes between the two machines. This includes ...
27
votes
4answers
4k views

How do you deal with massive port scans?

This morning I was looking through firewall logs and saw there were about 500 packets marked as port scan. The scanning range was from 1000-1200 5000-5200. The IP address is 85.25.217.47 which seems ...
26
votes
7answers
41k 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 ...
26
votes
6answers
31k 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 ...
26
votes
5answers
5k 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 ...
25
votes
10answers
6k 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 ...
25
votes
3answers
7k 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. ...
25
votes
3answers
1k 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?
25
votes
3answers
3k views

Does using a live CD make you more vulnerable to remote attacks?

Some people recommend the use of a Linux live CD for online banking, but doesn't that make you more vulnerable to network attacks since it's not updated? I tried installing updates and it required me ...
24
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 ...
24
votes
3answers
15k 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 ...
23
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 ...
23
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 ...
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
5answers
28k 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 ...
23
votes
4answers
7k 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 ...
23
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 ...