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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19
votes
6answers
13k views

Are some uncommon TCP ports scanned less than others?

Ignoring the top 5-10% of port numbers for common services that are the commonly targeted by port scanners (i.e. ports 22-ssh, 23-telnet, 80-http, 139-smb/cifs, 443-https, 3389-rdp, etc.), are the ...
19
votes
3answers
5k views

How Can I Process Untrusted Data Sources Securely? [closed]

Here is the conundrum: At my current company, we process physical discs from numerous third party sources and extract the data from them to ingest to our own system. While we can generally trust the ...
19
votes
4answers
5k views

Is strategic cyber-warfare feasible today?

Cyber attacks that target a nation's infrastructure are a documented fact and as such a danger that political and military leadership across the world needs to worry about and act proactively. These ...
19
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4answers
4k views

Detect non HTTP packets using port 80

We are currently doing port whitelisting on our firewalls which is working well but this of course does not prevent the implementation of side channels or the misuse of these ports for other purposes. ...
19
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5answers
37k views

Is UPnP still insecure?

In today's world, on equipment that is properly updated to the latest software/firmware, is UPnP still insecure, or have its vulnerabilities been fixed?
19
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3answers
6k views

Are open wireless networks unencrypted?

When you connect to an open wireless network (that is, a wireless network without any symmetric password set) is there any sort of secure key exchange going on, or is data sent back and forth ...
19
votes
4answers
62k views

How to tell if you're being ARP poisoned?

I am having some issues at work and there is a new network admin in place. I think I am being monitored so decided to run ArpSpy X in two scenarios: Over WiFi bridge plugged into Cisco router to took ...
19
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1answer
6k views

SFTP, FTPS and SecureFTP differences and security implications

What are the basic differences and security implications of using SFTP, FTPS and SecureFTP.
19
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4answers
4k 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 ...
19
votes
1answer
13k views

How can I detect real location of the user through their IP address?

There were many ways to detect the user's IP, for instance we could get it through a single click link or through any other medium of communication where we could get the user's IP. But the tedious ...
18
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6answers
3k 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 ...
18
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4answers
9k views

Can an attacker sniff Mac addresses on a wifi?

If an attacker turns on wifi but doesn't have the security key to connect to an access point in range, can he still sniff packets that travel between the access point and clients connected to the ...
18
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3answers
30k views

How do I ensure data encryption on Samba transmission on *NIX systems?

I have a heterogeneous system (both MS and *nix) that communicates with CIFS/SMB. How can I ensure proper data encryption at the application layer?
18
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1answer
13k views

Is it even possible to hack a television channel?

In spite of all the hacking news in the recent few years I never heard of someone who managed to hack a TV channel. What makes them so secure?
18
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3answers
5k views

Recommendations for honeypot software

A couple of us wanted to setup a honeypot/honeynet with the goal of learning; not planned to be in a production environment. What's a good recommendation for a high interaction or low interaction ...
17
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3answers
3k views

Why is it called a stateful and a stateless firewall?

I'm just wondering about the naming of these firewall behaviours. My basic understanding is that stateful filtering lets inbound traffic to return the outbound response without explicitly specifying ...
17
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3answers
55k views

How can I detect if someone is sniffing network packets on the LAN?

I would like to know if there is a product or software that can detect if there is a sniffer currently on the network? In other words is it possible at all to detect if there is a network card on ...
17
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8answers
22k 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 ...
17
votes
4answers
12k views

Best way to report a foreigner attacker's ip to authorities?

I have been under attack last week and I was able to trace down the attacker and get his IP address. The attacker was located in Germany but I live out of Europe? From your experience what is the ...
17
votes
1answer
4k views

Cybersecurity “Airport model”

For the last few months, I have heard about a next generation model of Cybersecurity called the "Airport model." Does anyone have more information about it?
17
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5answers
4k views

Why don't ISPs filter on source address to prevent spoofing?

I'm under the impression that if all the ISPs were required to filter on the source IP address of all outbound packets, that spoofing would be reduced considerably. Are any ISPs implementing this ...
17
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4answers
2k views

Network Forensics - what is in your toolbox

In similar vein to this question on computer forensics, what tools would you have in your toolbox for infrastructure and network forensics. Typical example cases would be if you were called in either ...
17
votes
4answers
58k 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 ...
16
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2answers
2k views

Hosting an “IP Rental” address. Is this common, safe?

I have a supposed opportunity to get in with an individual with advertising and a side business of his, renting IP addresses. He has asked me to set a dedicated DSL account at my house. Is there any ...
16
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4answers
39k views

Tips for a secure iptables config to defend from attacks. (client side!)

Own examples: ############### # KERNEL PARAMETER CONFIGURATION # PREVENT YOU SYSTEM FROM ANSWERING ICMP ECHO REQUESTS echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_all # DROP ICMP ECHO-REQUEST ...
16
votes
3answers
15k views

Running windows in virtual machine, should I bother with security?

I'm running Windows in a virtual machine on my mac (via Parallels). Should I bother installing antivirus, firewall and using other conventional wisdom practices (like don't open unknown .exe etc)? I ...
16
votes
2answers
23k 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, ...
16
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1answer
1k views

Do any DNS registrars support multi factor authentication?

I am looking for a DNS registrar that supports strong multi-factor authentication. Does any DNS registrar support multi-factor? Is this a legitimate need?
16
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3answers
1k views

What techniques and tools do you use to relate security events?

You have central logging going, detailed app logging/alerting (e.g. modsec), network based security alerting (e.g. snort), and whatever else feeding your observation deck. Do you have any cool ...
15
votes
3answers
5k views

Bruteforce attack on my FTP server

I recently setup VSFTPD on my personal server for sharing files over FTP. In the vsftpd.log file, i see hundreds of failed attempts to login with usernames like "adminitrator" , "adminitrator1", "...
15
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5answers
4k views

Are consumer-grade routers any more or less vulnerable? [closed]

I apologize if this is an obvious question, I'm not very familiar with hardware. I am planning on hosting a few personal websites from my home, but I'm concerned about my security. I'm using a fairly ...
15
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5answers
21k views

Can I block based on MAC address?

If I block an IP, the attacker can work around the block by taking a new IP or use a proxy. Is it possible to make a ban based on MAC address? I want to block at the webserver level so that unwanted ...
15
votes
5answers
3k views

What computer information can WiFi networks see? [duplicate]

I'm on a school WiFi network, and it's school policy to record basic PC info(name, IP, etc), along with the student name when they add the computer to the WiFi network. My assumption is that it's to ...
15
votes
5answers
700 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 ...
15
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5answers
4k 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 ...
15
votes
2answers
16k 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?
15
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3answers
3k 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 ...
15
votes
1answer
34k views

EAP-TLS vs EAP-TTLS vs EAP-PEAP

I'm having troubles understanding the differences between the 3. As far as I understand, with EAP-TLS, the client (peer) and the server (authenticator) both need a certificate. The authentication is ...
15
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1answer
1k 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 ...
15
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6answers
13k views

What reputable site should I download Putty from?

I recently did a Bing search for Putty and can only guess at which distribution is "trusted", contains no malware, or sleuthing code. If you needed to download Putty for a high security Windows ...
15
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3answers
1k 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?
15
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2answers
2k 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 ...
15
votes
1answer
2k views

Kaspersky Antivirus “secure connection scan” as broken as Superfish?

I've read a lot about Superfish (and similar ad-ware) lately and I basically understand the vulnerability to MITM attacks. But I'm actually wondering if the "secure connection scan" by Kaspersky ...
15
votes
2answers
6k views

How bad is the leaking of Internal IP addresses through external DNS

If an external DNS server is leaking internal IP addresses are there any significant security threats associated with this information leakage? Apart from most the obvious - gaining an understanding ...
14
votes
3answers
5k 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 ...
14
votes
7answers
713 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 ...
14
votes
4answers
27k 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.
14
votes
5answers
14k views

What kind of attacks against home router's NAT do exist?

I always thought NAT was some kind of a security feature and I still think it is, because if it didn't existed the internet, respectively the clients behind NATs, would be even more insecure, since ...
14
votes
2answers
6k views

What's the diff between blocking a port with a firewall and not starting a service on that port in the first place?

I was considering setting up a software firewall (pf) on my web server and did some research on them. Were I to do it, it'd involve basically blocking connections to all ports except 80, 443, and the ...
14
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3answers
16k views

What is the difference between SSH and IPsec?

There seems to be similar encryption going into both. They both use asymmetric (RSA, elliptic curves, etc) for the initial key exchange, then go to some symmetric (AES, Blowfish, etc) protocol. I'm ...