Network Security - securing network infrastructure and connections

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What is secure enough for web applications?

we intend to build a network in a small health center with No Internet Access it is expected to have 30 terminal machines, all machines will use an electronic medical record web application we want ...
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4answers
9k views

How to detect hosts running in virtual machines with nmap?

I have to determine if a given subnet has virtual hosts. Are there any ideas about what switches to use?
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4answers
826 views

IP Address spoofing?

According to: https://secure.wikimedia.org/wikipedia/en/wiki/IP_address_spoofing "this technique is mainly used when the attacker does not care about the response or the attacker has some way of ...
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3answers
6k views

Advantages of separating Web server from Database

What are the security advantages of installing the database of a web application on a server other than the one containing the web server?
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13k views

sniffing/recording GSM 3G signals

Is it possible to sniff or record and process GSM 3G signals (from some reciever) given that there is no other signals interrupting etc (the most comfortable conditions) Update (with some supporting ...
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3answers
4k views

Encryption on mobile phone - myth?

Well, about six months ago I had pleasure to meet Harald Welte and when he talked about m-banking (banking via smartphones) he said that the most people thing it's safe while, in fact, mobile ...
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4answers
1k views

How can a company reduce exposure to packet spoofing? What solution should exist, but doesn't?

I'd like to understand what anti-packet-spoofing technology exists (or should exist) to verify an inbound packet. Maybe this is as simple as a Cisco ACL, Firewall Rule, implemented at the network ...
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2answers
710 views

What does a Firewall mean by “connect to TCP port without your permission”?

McAfee is reporting incoming network connections blocked from IPs like 198.252.206.149 (StackExchange Inc.), 54.179.231.116 (Amazon Technologies Inc.), 74.125.68.106 (Google Inc.), etc. The ports ...
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1answer
1k views

Is it possible to recognise and prevent MitM attacks on devices which use self-signed SSL certs?

I use both Linux and Windows at work on a large enterprise LAN. The majority of the network configuration is out of my reach. Certain SaaS applications that are hosted locally on the enterprise LAN, ...
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3answers
7k views

Block all BotNets and TOR addresses from accessing our site

I've heard that many DOS attacks and general "black hat hacking" attempts occur over the TOR network. Is it possible for me to dynamically block source IP's by their presence in a BotNet or similar ...
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3answers
903 views

Is IPv6 with NAT less secure than IPv4?

This is a follow up to a snippet from another answer. There, user Ninefingers writes: (...) only allow outbound connections, ever. Do this in spite of NAT as IPv6 will make those NAT defences ...
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How can I restrict access to network data by an unauthorized computer that connects via Ethernet?

I assume I can configure most routers to only assign IP addresses to specific MAC addresses, as is possible with wireless routers. However what if a computer is connected via Ethernet and does not ...
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3answers
4k views

Risk of configuring MySQL for remote access with a dynamic IP address?

I'm looking to make a MySQL database on a VPS, accessible to my home PC through cPanel. cPanel wants the domain name or IP address of the remote machine. However, with standard DSL, I have a dynamic ...
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4answers
734 views

CAM table attack in 2011?

Today's switches are vulnerable to CAM Table attack? https://secure.wikimedia.org/wikipedia/en/wiki/CAM_Table
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3answers
494 views

Securing a LAN without Physical Security

I've got an interesting dilemma. I have a large (50+ users) office that is going to be on the campus of a local university. The purpose is to foster collaboration, etc, but the open environment is ...
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1answer
15k views

Are open ports dangerous?

I have forwarded port 80 to WAMPServer and 25565 to the MineCraft-server running Bukkit. (http://www.bukkit.org/) Am I vulnerable to attacks. Can hackers attack me if WAMP-server is running or if it ...
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2answers
515 views

How to secure a modem/ wifi router without login?

A friend of mine has a DSL-modem/wifi-router from his ISP. The configuration page of the modem requires no login and no login can be set. It is said that there also exists a superuser but this is only ...
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1answer
520 views

Is the system bios and network card protected by the OS firewall?

My question arises from trying to understand new types of spyware that target the system bios and/or network card. Is the system bios and ethernet card both protected by an OS firewall set to deny ...
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2k views

Spoofed IPv4 and IPv6 addresses over the internet

I have a few questions regarding IPv4 and IPv6 spoofing. Might as well just list them to be concise: What's the usual routing policy for ISPs' routers in regards to spoofed source addresses? i.e. if ...
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249 views

Retaining institutional knowledge of a complex infrastructure (checkpoint, juniper, etc)

In the next month my functions will be expanded to include IT security (firewalls, VPN, PKI) in a big complex infrastructure. Can I ask you for advice on how-to be well prepared for it? What sorts of ...
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10k views

Securing remotely accessible IP cameras that do not support HTTPS

I have some IP cameras set up on my home network, which is WPA2 protected. These cameras are setup to be accessible from the Internet thru my router's DDNS address, and port number. So for example, ...
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1answer
244 views

Are multiple network interface still recommended in a virtualized world?

Before the virtualization era, it was recommended to have several network card on a physical server : 1 for production dedicated network (only application's stream like http, SQL*NET, ...) 1 for ...
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1answer
1k views

How secure is the apt-get install command against man in the middle attacks

I think the title says everything, how secure is it to use apt-get in a network with an attacker who injects his own packets and blocks the original packets (man in the middle).
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How do the root servers get updated with my name server? Is WhoIS information always in sync with the root?

I've never understood what happens behind the scenes when I go to my registrar and enter in my name server's information. Can someone elaborate on what happens when an update is made, and how it is ...
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5answers
3k views

Creating tunnel with most ports closed?

How can I create a proxy tunnel from a network that has all ports but port 80 closed? I guess I'd have to bind SSH on my server to port 80, but would that introduce problems to my home network since ...
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4answers
31k views

Pros/cons of using a private DNS vs. a public DNS

I was wondering why a company should use a private DNS. In comparison with a public DNS, which advantages does a private one have, and which issues can a public DNS create for a company? I'm new at ...
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1answer
307 views

What is the security vunerability in this scenario?

I saw this question: Suppose a university with address block 12.1.0.0/16 has a link connected to AT&T, where the AT&T router forwards packets destined to 12.1.0.0/16 to the university ...
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1answer
476 views

Is Chinese great firewall white or black list based? [closed]

Is a new website blocked by default in China ? I just put online a new website dedicated to chinese people (a working days calculator in China, nothing subversive indeed). However a friend of a ...
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3answers
334 views

Can you tell if an attack is successful by looking at IPS logs?

In my organization, we have an IPS behind a firewall. Each time a security event is triggered, I am left to wonder if the attack is really successful. For events that are set to drop in inline, we can ...
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1answer
838 views

What are the main issues and best practice security controls when exposing SIP and H.323 to the Internet?

What are the main issues and recommended controls when exposing SIP and H.323 to the Internet (could be for voice, video, and instant messaging traffic or all three)? Specifically I'm looking for ...
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3answers
706 views

How can an IPS be fingerprinted?

I'm not trying to solve a current technical problem but I came across this and have been wondering how it's done. Intrusion Prevention Systems are supposed to let all network traffic pass through and ...
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2answers
783 views

Does DNSSec have any benefit if used with IPSec-enabled IPv6?

I'm not sure if the RFC's support a IPSec-only implementation of DNS, but if it does, what does that mean for DNSSec? Is DNSSec an IPv4-only technology?
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1answer
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What are the vulnerabilities of VOIP-specific security protocols?

Existing relevant questions: How do you Secure VOIP in a large organization What are the main issues and best practice security controls when exposing SIP and H.323 to the Internet? Do secure phone ...
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1answer
4k views

How to create your own RBL DNS Blacklist to prevent spam

I am getting sick of reporting the same old chinese emails to Spamcop now and would like to make my own small RBL list that I can easily add blocks of IP's to. I have a spare PC and static IP address ...
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4answers
6k views

Can I block the true IP address using X-Forwarded-For header in IIS?

All the traffic gets to my IIS server through a proxy. I can't block or white list IP addresses because all the traffic comes from the proxy's IP address. Can I use the X-Forwarded-For header with ...
8
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1answer
409 views

Can ICMP Redirects still be used to redirect traffic in a LAN?

I tried just tried to migrate a MITM attack using hping3 with ICMP Redirects in my testlab. hping3 -I eth0 -C 5 -K 1 -a 192.168.2.1 --icmp-ipdst 192.168.2.15 --icmp-gw 192.168.2.100 --icmp-ipsrc 192....
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Management Network Best Practices

I am looking at setting up a Management vlan, on which I will put all the Management interfaces for my various networkable devices (Firewall Mgmt Interfaces, Server RAC, WAP Mgmt Interfaces, etc). ...
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1answer
623 views

SSH Brute Force Dictionaries

Request for logs please. So, I had an interesting question posed to me around geographical trends in SSH brute force attempts. The question being "has anybody ever looked into the prevalent SSH ...
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1answer
293 views

Using / finding covert channels in inter-process communication

I've got a class exercise that involves a virtual game of Werewolves/Mafia. We're not really taught how to do anything in this class, which makes it hard for everyone to do the labs. The idea is that ...
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4answers
1k views

What is War Dialing?

The topic says it all - I encountered the term in a PDF given to me. So ... what does the term/phrase 'War Dialing' mean?
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1k views

Why would a switch be configured to Fail Open?

I can't understand why a switch would be configured to Fail Open? Surely an attacker could easily exploit this by MAC Flooding which will cause the switch to act like a hub and broadcast messages to ...
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6answers
323 views

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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5answers
11k views

Prevent network users from creating an unauthorized outgoing VPN connection to avoid network policies

Is it possible to prevent network users from creating unauthorized outgoing VPN connections to avoid network policies? Edit- What is the best way to detect unauthorized outgoing VPN connections while ...
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2answers
3k views

Dictionary Attack on Wifi

I know a few people with pretty weak passwords. What kind of systems exist to prevent dictionary attacks? Would it make sense to restrict the number of connection attempts in a certain timeframe? ...
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732 views

Is Stonesoft's “advanced evasion technique” a major problem?

A month ago, Stonesoft (an IDS constructor from Finland) has launched an alert about Advanced Evasion Techniques. With these techniques, they claim to be capable of launching attacks on a network ...
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4answers
4k views

Security Services on Edge Router vs. Standard Firewall

If I can run a site to site VPN, NAT & Reflexive ACLs on a edge router (plus normal routing functions), what would be the use of running a stock firewall behind it? For instance, Core Switch --> ...
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3answers
4k views

TCP Sequence Prediction and it's prominence in modern systems/networks

I have a question regarding your experience of TCP Sequence Prediction that I am hoping someone could help with. I am aware of how TCP Sequence Prediction works and how the connection can be hijacked ...
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300 views

What to add to a repeating security checklist?

I work in a smallish company (100-200 computers and a handful of servers) and I am trying to come up with a checklist of things to check at a regular basis, such as weekly, monthly, etc. We use ...
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3answers
6k views

What makes the Blackberry device and network more secure?

One of Blackberry's strongest assets is the "network" that it uses. Can someone explain, or link to technical information that covers what this secure network is, and what it does better than the ...
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2answers
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IIS IP Address Restriction - can I rely on it online?

I've been told that I might have more luck posting here than on Stack Exchange, so here goes: I'm looking for a way to lock down a 3rd party application in IIS. It's a web service, so there's no ...