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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32
votes
8answers
111k views

Why is WPA Enterprise more secure than WPA2?

In personal mode WPA2 is more secure than WPA. However, I have read that WPA Enterprise provides stronger security than WPA2 and I am unsure exactly how this is achieved.
32
votes
7answers
8k 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 ...
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, ...
31
votes
3answers
15k 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; +http://...
31
votes
4answers
9k views

How can my IP camera be hacked behind a NAT?

I keep reading about hackers accessing laptop and home security camera systems. Most home users are using SOHO routers meaning they are on a private IP range behind a NAT. I realize NATs aren't ...
30
votes
6answers
13k views

Is pinging a website essentially the same as visiting the website through a browser?

I was looking at the domain information of a website (poaulpos.net) on who.is that Chrome connects to whenever I visit a specific an old Tech Times article about Thunderstrike 2, a Mac firmware attack ...
30
votes
5answers
43k 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?
30
votes
3answers
11k 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. ...
30
votes
6answers
43k views

How to design a home network for IoT devices?

I'm trying to work out how best to design a home network which contains (potentially hostile) devices. I'm running into my limits of networking knowledge! I have two challenges. Unsecure Devices ...
29
votes
5answers
6k 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 ...
29
votes
7answers
45k 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 ...
29
votes
5answers
10k 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 ...
29
votes
3answers
6k 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
7answers
3k 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 ...
27
votes
10answers
9k 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 ...
27
votes
4answers
7k views

What security mechanisms are used in BGP and why do they fail?

I just read about Indosat trying to take over the Internet by mistake. I read on a Polish infosec-related website that most of their announced routes failed to propagate, but some of them reached the ...
27
votes
3answers
2k 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?
27
votes
4answers
9k 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 ...
27
votes
3answers
23k 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 anyways)?...
26
votes
1answer
50k views

TCP Peer unexpectedly shrunk window messages in dmesg log

We get quite few messages like these in our dmesg log on various servers: TCP: Peer 0000:0000:0000:0000:0000:ffff:d431:5861:56369/80 unexpectedly shrunk window 2522304441:2522312601 (repaired) TCP: ...
26
votes
1answer
7k 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 ...
26
votes
3answers
4k 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 ...
25
votes
12answers
64k 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 ...
25
votes
5answers
5k views

Internal network address contains my name - problematic?

In my university, I needed to register the MAC address of my personal laptop with the admin in order to use the university network. Now, it seems like I am assigned a unique network address "lastname....
25
votes
1answer
48k views

OpenVPN Tap vs Tun Mode [closed]

I would like to know practical difference between TAP and TUN mode when use with OpenVPN. When to use TAP and When to use TUN ? What types of traffic will pass with both mode ?
24
votes
8answers
6k 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 ...
24
votes
8answers
9k 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 ...
24
votes
7answers
2k 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 ...
24
votes
6answers
6k views

What security risks does IP spoofing bring?

By manipulating the TCP packet and changing the source address one is able to spoof the IP. As I understand it, you will not be able to set up a full handshake by doing this, as you will never receive ...
24
votes
4answers
4k views

IPsec (Internet Protocol Security) facts

Internet Protocol Security (IPsec) is a successor of the ISO standard Network Layer Security Protocol (NLSP). What are the advantages, disadvantages, other interesting facts regarding the protocol?
24
votes
3answers
3k 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 ...
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
1answer
6k views

AWS VPC - should connections between instances be over SSL?

Say I have a few EC2 instances in an AWS VPC network, each assigned its own private address for the subnet at creation. Say one of them is a DB, and another one some kind of web app talking to the DB. ...
23
votes
7answers
4k views

How can I publish data from a private network without adding a bidirectional link to another network

I was just wondering how I could build a private network where it is physically impossible to gain access from outside but still have the option to publish data to some remote server. As an example: ...
23
votes
5answers
7k views

Access to a router's GUI

During a recent visit to a coffee shop, I noticed that they hadn't bothered changing their default user name and password for their router. I realise that someone could log on and be annoying to ...
23
votes
5answers
4k 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. ...
23
votes
2answers
10k views

Reject IP packets with an ICMP error, or just drop them?

Consider an internet-facing host (the outer firewall). What should be done with undesired traffic: just drop it, or send back an ICMP error such as port unreachable? (In Linux terms: iptables -P DROP ...
23
votes
2answers
3k views

In what scenarios is relying on source IP address as a security control acceptable/unacceptable?

A number of questions on this site mention relying on source IP address as a control and in most of them it is dismissed as being unreliable. In what circumstances might using source IP address as a ...
22
votes
3answers
54k views

How does “traceroute over TCP” work, what are the risks, and how can it be mitigated?

There is a utility called tcptraceroute, and this enhancement called intrace that is used just like a standard traceroute, but it works over TCP. How is the syn flag in TCP used to achieve traceroute ...
22
votes
2answers
950 views

Why on earth would anyone use the 'top secret' option of IPv4?

So, I was reading RFC 791, and got to the bit about options (here). Everything seemed to be decent and sensible, until I got to the 'levels of security' part. Now, I can understand how, internally, ...
21
votes
4answers
31k views

How are spoofed packets detected?

My assumption: When a firewall is configured to drop spoofed packets, it tries to ping (not necessarily ICMP) the source IP and sees if it belongs to a real host or if it's up, and if not, it drops ...
21
votes
3answers
6k views

Should a hostname ever be considered a secret?

I've been told in the past that you should never give out the host names of computers on your network. I can't think of any reason why this would be the case. Could someone tell me if they should be ...
21
votes
5answers
14k 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 ...
21
votes
1answer
13k views

Is SOCKS secure?

In order to create a VPN, I open an SSH tunnel with a command like ssh -D 9000 user@host, and then I set my system's proxy settings to use SOCKS5 through localhost:9000. Well, setting up my home ...
20
votes
6answers
39k views

What is the best practice for placing database servers in secure network topologies

I have a classic DMZ architecture: My webserver is placed in the DMZ. The webserver needs to communicate with a database server. This database server is the most critical component of my network as ...
20
votes
9answers
6k views

Securing a LAN that has multiple exposed external Cat 6 cable runs?

We're evaluating putting in an IP-based CCTV system for a third-party upcoming project (part of a wider networking project). The CCTV system is cabled as follows: Cat 6 running from each external ...
20
votes
4answers
32k views

DHCP vs. Static IP Addressing

How do DHCP and Static IP addressing compare, from a security standpoint? What are the risks/benefits associated with each? I know the preferred solution between the two will vary with network size ...
20
votes
4answers
17k 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 ...
20
votes
3answers
6k views

What are the risks of using a CDN to speed up my website? How do I avoid them? [duplicate]

Content Delivery Networks (CDNs) are well known to speed up the performance of a website, but they create the obvious security risks if someone were to change the code that resides on the CDN. What ...
19
votes
5answers
3k 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 ...