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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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What information can be gained from an Email Header?

What information is present in an Email Header that can be used to track a sent mail? For example, are some of these present? Web Browser used? Operating system Type of Network (broadband/dial up)? ...
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Shellcode Injection/Poisoning on Mobile Networks[GSM/LTE/CDMA-varaints]?

In the previous question(How do APN hacks work?) I have enquired about APN hacks but after reseaching more about cellular networks. I wonder has anybody attempted Remote-code execution/poisoning,etc ...
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1answer
320 views

Accessing WPA/WPA2 password from native auth form on a rogue router

I'm trying to wrap my head around the WPA/WPA2 4-way handshake in an attempt to determine if it is possible for a rogue wireless access point to retrieve a plaintext (or hashed) version of a router's ...
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1answer
251 views

Multiple Independent Levels of Security vs Multilevel security

I am looking for a way to isolate two different networks from each other. Suppose we have 2 different networks (public and private). I am looking for a way to connect to these two networks via a ...
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2answers
273 views

Only HTTP(S) port is open. Why do I need to worry about unpatched software?

Unpatched software poses no risk by themselves. They're only problematic when someone exploits it. How could malware get into my system if I do have unpatched software in general and I'm connected to ...
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4answers
338 views

Basic question about why it's useful to have VPN encrypt traffic

There may be a basic flaw in my understanding of how the internet works so sorry if this is a simple question. What type of attack does VPN protect against? For example if a local area network (let's ...
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Are there valid reasons for spoofing an address?

This is a corollary to the question Why don't ISPs filter on source address to prevent spoofing?. Are there valid reasons to spoof an address?
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How did the spammers get this address?

A few months ago I configured a test mail server on Amazon AWS, all legit. I used a new address to my catchall-domain (something similar to, but not exactly, test-config-aws-neptune-2014-08@my-domain....
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2answers
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Online SQL Server database for a Business app. Security considerations

A business application works with a SQL Server database. A SQL Server 2008 is installed on one of the computers of the local network. Technically this app works OK if the server computer with the SQL ...
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6answers
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Why shouldn't I run other applications on a Firewall?

If I want to use Ubuntu 11.04 as a Firewall in SOHO environment, then I just can't figure out what is the bad thing about installing GUI on it (e.g.: XFCE)? The only opened port to the world (wan ...
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1answer
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Evil twin access point with WPA/WPA2

When I created an evil twin AP with an SSID of someone else's Wi-Fi network e.g. MyWifiNet, I could see two APs on my phone/laptop with the SSID MyWiFiNet, however the legitimate one was secured with ...
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773 views

“There's a firewall on the router into the building so you can turn the one on your computer off”

I know some people that, in regards to network security, argue that because the firewall on the router into the building is on, that makes the network secure and therefore, the firewall on Windows PC'...
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1answer
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Is indirect access to a computer as bad as direct?

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 not to allow the server machine to connect ...
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1answer
338 views

How to spare file server data from being held hostage by client ransomware?

Suppose in a network there is a file server which's storage is shared between all workstations and all users require full read/write access to this storage for their cooperation workflow. (Over samba, ...
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Strange 'agetty' process running on my VPS.

Recently, I had to reinstall one of my VPS servers (again), due to malware. I took what I considered to be pretty good security precautions. I also locked the root account and am using sudo as well. ...
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2answers
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incoming packets in server

I have enabled iptables logging for packets coming from the outside -A INPUT ! -s 192.168.218.0/24 -j LOG Now i am seeing lots of incoming packets from unknown addresses Jun 5 14:54:56 localhost ...
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How can an IPS\IDS detect SQLi \ XSS (or other application layer) attacks?

I've been thinking about how an IPS works, and as far as I know it inspects the packets on the TCP\IP layer. How can it detect attacks on higher levels without harming the user experience? How does ...
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3answers
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Is there a way to identify the host of a malicious VM from across the network?

Scenario: Someone is attacking your network. However, they're not exactly using their machine to do it - they're using a VM running on their system. The VM's network adapter is configured in "...
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1answer
2k views

How does a device send the Wi-Fi password to the router? [duplicate]

When I connect to a Wi-Fi network I know the password of, how does the device send the password? Specifically, what prevents the network next door from catching that message and thereby learning the ...
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2answers
93 views

IPSEC connection attempt to rogue server — is my PSK compromised?

I am setting up an IPSec connection between two sites using Ubiquiti EdgeOS-based equipment. Using a DDNS service (a static IP is unavailable from the ISP), they can be found at east.example.net and ...
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3answers
199 views

Single web application - security advantages to two server model?

I'm looking to deploy infrastructure for a web application that will live on a LAMP stack. The infrastructure is such that this is the only application that will ever live on this server and it must ...
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2answers
717 views

DNS cache poisoning

What are the things the attacker needs to know from the victim to perform DNS cache poisoning ? for example : IP , Port number and Transaction number what else ?
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1answer
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Hubs, Switches, and Bridges - Flaws and Security Superiority

It just isn't clear to me which choice is good for creating small/intermediate networks. I know one of flaws of Hubs is that they send all packets to all nodes connected to it, in contrast to Switch ...
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3answers
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Is SSL Interception possible without disabling Public Key Pinning on the client side?

I'm currently setting up a pfSense firewall in my lab. It supports SSL Inception which works pretty well for most sites. But there are some sites which use HTTP Public Key Pinning to prevent MitM ...
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Is there a compelling reason to ssh tunnel RDP connections?

We don't run any Microsoft products natively in our office, but there are a few folks who use a linux RDP client to access an application on remote virtual desktops with a service provider. Would it ...
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1answer
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Filtering network access on a user/group/process basis

I am interested in peoples thoughts on what the best approach would be to controlling access to network interfaces at a user/group/process level for a Linux based host. The scenario I have in mind is ...
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1answer
770 views

What is known about the sirefef/zeroaccess malware/botnet?

There appears to be an increase in p2p communication among botnets that has been attributed to the sirefef/zeroaccess malware botnet. What is known on this particular threat?
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4answers
631 views

Learn about network and security for securing a server

I'm setting up an OpenBSD server that I want to connect to the Internet (it's going to be used to host a site - so, with Apache, SQLite and the like). I want it to be as secure as possible. Social ...
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3answers
746 views

Can all internet traffic from a smart phone be encrypted?

HTTPS and other encryption methods help prevent targeted advertising, tracking, and information theft. Tools like HTTPS Everywhere can attempt or require HTTPS in web browser connections. Are there ...
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4answers
514 views

What does a switched network protect us from? What does it not protect us from?

There seems to be some misconceptions regarding what a switched network will protect us from, and what technologies/precautions a secure environment requires when segmenting trusted users from hostile ...
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3answers
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Could a neighbour see my traffic when we have cable Internet?

Is it possible that a neighbour could see my traffic (*), when we both have cable Internet? Or: Under which conditions might this be possible? I would assume, "Never!", but after reading these two ...
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3answers
541 views

Repudiation in Copyright Infringement (BitTorrent)

Seeing this question : How can alleged illegal downloading be detected? sparked a question I have had for a long time. How does repudiation/non-repudiation work in such cases ? Argument: It is known ...
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3answers
721 views

VPN server in a router [closed]

I am new to using and configuring VPNs. I was thinking of setting up my router as an OpenVPN server, but as I understand that is to connect form the outside to my network. However, I want a connection ...
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1answer
325 views

Maximum protection on a computer network?

I would like to secure as much as possible a computer I am using to sync sensitive data files from work to my home pc. The syncronisation is being done by only 1 software is there a firewall to allow ...
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3answers
4k views

Identify a process that uploads data

I am using the tool "Internet Traffic Agent" to monitor my in- and outbound traffic. It shows me clearly that over a period of approx. an hour, some process on my machine is uploading data, about 200–...
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2answers
320 views

Which private-key encryption should I use for server to server communication?

I am tempted to write my own which covers: Checksum to ensure data is not tampered with. Long and multiple rotating keys so that it is (practically) impossible to decrypt. Will use /dev/random for ...
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5answers
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Cannot identify or block unknown MAC addresses (Part 2)

Previously, I mentioned 5 unknown MAC addresses often connecting to my router, and noticeably causes my internet to be slow. Router: Tenda D303, Location: India, Connection: BSNL Unlimited 1Mbps ...
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2answers
4k views

Dual Firewall DMZ

We've just learnt about firewalls and DMZ and I'm struggling to understand how are these actually implemented ? The architecture we've learned was something like this: Let's say that we have a ...
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1answer
13k views

House owner can see who's connected to WiFi; what more can he see?

I live in a rental house, and use the house-owner's wireless network to connect to the internet. The owner can see who is connected to his wireless network and I had a few questions regarding this ...
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2answers
71k views

Router admin password was changed, how did this happen and how to prevent [closed]

Internet was extremely spotty for about a week. I was on/off cycling the cable model and router almost daily, before I tried to sign into my router (198.162.1.1). When I did I was presented with a ...
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1answer
2k views

Encrypting layers of OSI

I was reading that WPA2-PSK encrypts layer 2 of the OSI network model. What is the danger of having this layer in plaintext (I know it can be decrypted very easily from within the network)? Is there a ...
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2answers
264 views

Has networking using multiple “unrelated” connections to share an encrypted data stream been researched?

I'm not exactly an expert, so I'm hoping you'll give me the benefit of the doubt and try very hard to make sense of this... I've been thinking about a simple measure, which I'll call Multiple ...
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1answer
510 views

Is using a local DNS cache server more secure than using a DNS server from a router?

Is using a local DNS cache server imore secure than using a DNS server from a router?
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948 views

Why there are uninvited incoming packets to my ADSL connection?

To verify this, I boot my PC from Kali Linux live distro. Before establishing ADSL/PPP connection, I start Wireshark and listen on any pseudo device. Then I create the connection to ISP network. ...
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1answer
104 views

Encryption on Mobile Devices - Multiparty Encryption - Key Management

I have the following setting: Let A, A', A'' be different mobile devices. They want to sent a secret message M to all (or some of) the C,C', C''. The message is passed on to B that stores it for some ...
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1answer
3k views

Does a network behind a NAT\modem firewall need a firewall?

Would it be justified for a business that is behind a SOHO router\WIFI to run a firewall such as PFSense, or is the firewalling capabilities in the router "good enough". For the most part the router ...
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1answer
3k views

syn flood size per second

Given the size of a TCP packet is 60 bytes, there is a SYN Flood attack on a computer made ​​by a 100 Mb bandwidth, the question is how many syn packets are sent in a second? Is there any formula for ...
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1answer
301 views

Can accounts still be logged onto if Password Caching is not enabled?

This is kind of an extension of my other question.. If you were not storing any of the passwords locally (caching disabled), would a user some how still be able to circumvent around this security ...
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2answers
825 views

Separate networks on one modem for security reasons

I'm not very familiar with networking issues, but my current project requires me to create an environment in which I will have 2 clients, but client 2 cannot see where client 1 is connected to and ...
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1answer
2k views

How to write Snort rules based on MAC address?

I would like to create Snort rules based on MAC addresses instead of IP addresses. Most devices on the network are DHCP assigned, and I would like to ignore certain traffic (ex: Dropbox) for some ...