Network Security - securing network infrastructure and connections

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14
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4answers
1k views

Threat assesment for a captive portal

I am interested in setting up a captive portal on a wireless network. From what I understand I would do this by initially having all guests in a temporary vlan, moving them to the real vlan when ...
14
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4answers
1k views

Can I avoid DNS spoofing by typing the IP address?

The question is in the title. I have been reading about DNS spoofing. What if I were to save the IP addresses of websites I consider sensitive and then just enter the IP address when I am using a ...
14
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2answers
537 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, ...
14
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1answer
597 views

Are there any security problems with Google false start for TLS?

Google recently announced false start in Chrome browsers which increased TLS performance by 30% http://news.softpedia.com/news/Google-Chrome-s-SSL-False-Start-201253.shtml I know TLS has been poked ...
13
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3answers
3k views

Nessus vs third-party scans

As part of our PCI-DSS compliance process we get scans done by a third party. Based on the form and wording of the output, it's pretty clear they're using Nessus for most of their heavy lifting. Same ...
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5answers
2k 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 ...
13
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6answers
1k views

Defamatory post - obtaining evidence tracing perpetrator right to his laptop

A month ago, someone posted an ad with my personal details, including my home address, my phone number and my photo on an ad with very a very defamatory write up. What followed was a week of calls ...
13
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3answers
11k 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 ...
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2answers
6k views

How do Intrusion Detection Systems (IDS) work?

How do Intrusion Detection Systems (IDS) work? As I understand it, they monitor network traffic but what exactly do they look for? How can they tell apart regular activity from intrusions?
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6answers
4k views

Why is ARP poisoning killing all network activity?

Using ettercap and ARP poisoning, I was able to eavesdrop on other connections, but suddenly I was unable to make any connection to the Internet. To restore Internet connectivity, I had to restart my ...
13
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3answers
1k views

VPS security best practice

I've just signed up for a linux VPS to host a website I've been creating and I need some advice on the best approach to secure it. I've previously been hosting it off a VM in the house, but I want to ...
13
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2answers
519 views

Network policies under AppArmor/SELinux

I am attempting to sandbox some untrusted processes using Linux's MAC frameworks -- either SELinux or AppArmor. I see that both SELinux and AppArmor allow the selected granting of socket level access ...
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8answers
1k views

Randomizing MAC addresses on bootup

Since it is possible to set custom MAC addresses, wouldn't it make sense to have a new one as often as possible/convenient (i.e. on bootup)? It would seem that is useful to both attacker and victim ...
12
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5answers
15k 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?
12
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7answers
420 views

UNIX Servers: Possible intrusions or attacks that do not use any of the open listen sockets

What type of attacks are there that do not use open TCP or open UDP ports? Is it safe to assume that no open ports means no remote access? (Excluding the possibility that there is a badware already ...
12
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5answers
465 views

How can citizens prevent government-led Internet blackouts?

The United Nations now considers Internet access a basic human right. [PDF] Despite the questionable effectiveness of Internet blackouts in silencing a populace and preventing uprisings1, it's ...
12
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4answers
5k 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 ...
12
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5answers
7k 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 ...
12
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3answers
328 views

Verifying server software integrity?

I'm trying to brainstorm a security scheme for the problem of verifying server software integrity. The domain of this problem is Game Servers built on Valve's Source Dedicated Servers. These servers ...
12
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2answers
3k 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 ...
12
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4answers
580 views

Wireless Activity Monitoring for PCI DSS Compliance

In an effort to be PCI DSS compliant, I took a trustkeeper.net questionnaire. I failed the question that asks Is the presence of wireless access points tested for by using a wireless analyzer at ...
12
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3answers
2k views

How are mobile telephony networks like LTE and HSPA encrypted?

How are mobile telephony networks like LTE (4G) and HSPA (3G) encrypted? between what parts is the communication encrypted? who has access to the keys? is symmetric or asymmetric encryption used? is ...
11
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6answers
3k views

How can mini-computers (like Raspberry Pi) be applied to IT security?

It's no secret that thousands of $35 Raspberry Pi (Model B) computers have just shipped to people around the world. With these, and other similar types of computers becoming cheaper and more ...
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1answer
4k views

SFTP, FTPS and SecureFTP differences and security implications

What are the basic differences and security implications of using SFTP, FTPS and SecureFTP.
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1answer
3k views

Is WPA2 WiFi protected against ARP poisoning and sniffing?

Is WPA2 WiFi protected against ARP poisoning? If not, can the ARP poisoner decrypt the packets?
11
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1answer
519 views

XKCD #936: under what assumptions is 1000 guesses/second over a network plausible?

In XKCD #936, a rate of 1000 password guesses/second is proposed as a "plausible attack on a weak remote web service". Under what assumptions is this rate plausible? It seems much too high to me. I ...
11
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4answers
636 views

What is the risk of a packet being sniffed when travelling over the internet without SSL/TLS?

We all know to use SSL/TLS to stop people eavesdropping on our connection, but how likely is it that an attacker will actually sniff your unencrypted password or cookie if you don't? If we exclude ...
11
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4answers
301 views

What free tools or techniques exist to discover anomalies in network flows?

I have been using FlowMatrix. What do others do on the cheap?
10
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4answers
7k 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.
10
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4answers
4k views

Security measures against packet sniffing

I work in a environment where packet sniffing can be easily done . I was worried about my confidential data . Please suggest how is it done and precaution which i can take at client level.
10
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6answers
382 views

Should we configure all devices to never request SSL 2.0, and reject it if offered?

In an effort to reduce man in the middle attacks, when will it be (or was it) an industry accepted practice to reject SSL 2.0 connections on the client and server side? Is configuring this on a proxy ...
10
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4answers
2k views

How can an access point spoof me into connecting?

I was reading through the answers of the question "How can I ensure that I connect to the right wireless Access Point?" and was wondering how it is possible for an access point to imitate another wifi ...
10
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7answers
2k views

Egress filtering on an office network?

With an office network most companies will use ingress filtering to add a level of security, however few take advantage of egress filtering to protect their networks. The use of egress filtering will ...
10
votes
2answers
4k views

How to get MAC addresses of devices which are not in the network

Can I get MAC addresses of devices (mobile phones) which are near to my network but not connected to it? (Linux) I have been trying to get the MAC addresses of devices connected to my network through ...
10
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3answers
493 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 ...
10
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4answers
4k views

Looking for botnet IP address feeds to protect against DDoS

I would like to get a live feed of botnet IP addresses delivered from a service and block them under certain conditions. Preferably community based/open source but open to looking at worthy commercial ...
10
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5answers
1k views

What firewall settings on a Macintosh are the most restrictive, while still permitting casual internet use?

I don't want this to be subjective, so I'll try to make the requirements as clear as possible. On a Mac with Snow Leopard, how can I set up the firewall rulesets that allow ONLY: Using the internet ...
10
votes
7answers
636 views

IP address black list

My website has a black list of IP addresses. The web application, in some way, detects all invalid, suspicious influences to it and remembers IP address and denies any requests from that IP address. ...
10
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4answers
3k views

Is NTP vulnerable to DNS poisoning or spoofing attacks?

Scenario: Attacker somehow compromises the DNS lookup for the NTP server used by the victim (a web application) Victim sends DNS request for e.g. ntp.pool.org, which is responded to by attacker to ...
10
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6answers
1k views

Alternative to VPN

We have a network that is completely closed to the outside world. It needs to be. Problem is we need to remote into a server on this network once in a blue moon for diagnostics. We've discussed ways ...
10
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1answer
1k views

Native rsync protocol security

Is the native rsync protocol (port 873) secure? Does it encrypt data or credentials? I'm planning on using rsync to store encrypted files in the cloud, I'm wondering whatever the password is ...
10
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1answer
2k views

Backtrack 5 in a VM - Why bridged networking over NAT?

When running Backtrack 5 from a VM, it is recommended to use the bridged networking option instead of the NAT networking option? How does it affect the usage of Backtrack - port scanning, ...
10
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3answers
1k views

Is a predictable MAC address a risk?

If you knew from the public internet that a certain IP address belonged to a machine with a certain MAC address, can you see any security exposure associated with that? I know that some software will ...
10
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3answers
606 views

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?
10
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4answers
2k views

Is my network being sniffed?

Is there any way to find out if someone who is connected to my network is sniffing packets? There is a way with nmap if his card is in promiscuous mode but what if it is passive?
10
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3answers
371 views

Tools needed to setup a paranoid remote backup server

I'm a system admin with little security experience. I want to schedule the copying of our backups to protect our data in case of fire. The best solution would be to copy the data onto a new ...
10
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2answers
592 views

What is a “pre-play” attack?

I understand what a replay attack is, but I keep reading about a pre-play attack. What is it? Is it when someone intercepts an unused message and blocks the sender so they can't finish using it, and ...
9
votes
5answers
2k views

Can voice chat be spied?

I wonder if voice chat (via public services like yahoo, google talk, skype, etc) is practically secure? Is it possible for the ISP or any middle point? I do not consider hacking the computers, but ...
9
votes
8answers
674 views

Battling Malware without spending money

Our environment consists of about 80 users running Windows 7. Previous to me showing up as a full time IT employee, the company had contracted an outsource IT solution. As part of their set up, they ...
9
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3answers
550 views

Would publishing a network diagram make the network less secure?

I have found some social networking sites that focus on sharing architecture (network maps and diagrams) and configuration. Does sharing this type of information decrease the security of my network? ...