Concerned with software or hardware firewalls

learn more… | top users | synonyms (1)

1
vote
1answer
19 views

Security implications of packets with an invalid state (iptables)

I have been seeing few rules with -m state --state NEW, ESTABLISHED, RELATED. First I thought that was pointless as it was contemplating the three possible states, so there was no need to define -m ...
1
vote
2answers
34 views

Why the Websense blocks same site when used with http & not when used https? [on hold]

I have been working in a IT firm. I have access to some social sites. When I try to open site Links in mail (that are having http://), the websense prompts me that the access is blocked. However, when ...
2
votes
2answers
105 views

How common is port-knocking? [on hold]

Today I read about port-knocking for the first time. It has been a pretty known concept for more than ten years, but I don't know anybody who uses it for their servers. How common is the usage of ...
1
vote
1answer
43 views

Should reverse connections be used to bypass NATs?

I'm planning on doing a demonstration on how remote administrative tools work for my schools computer security club. I plan on writing a RAT in C++ and demonstrating/explaining how it works. I ran ...
0
votes
0answers
15 views

Which IPTables chains should I log from a security perspective

So far I've always been logging the INPUT and OUTPUT chains because I only used iptables as host firewall. Now I'm configuring network firewall which uses iptables, but I don't know whether I should ...
0
votes
1answer
43 views

Creating a secure home network - Which firm ware should I use and how should I configure my firewall?

I am starting to take on more and more enterprise clients while working remotely from my home office. I have a pretty secure network at the moment, but I have a lot hardware that I am not using and ...
-1
votes
0answers
38 views

Any good Alternatives to ControlScan PCI SQA? [closed]

My company is about to engace ControlScan for their PCI 1,2,3 solution giving us enough to have our hosting and service PCI compliant. Basically We are in need of a good Web Application Firewall, a ...
0
votes
2answers
125 views

Trying to get rid of hackers who have access to all my devices

What is the best way to go about getting rid of hackers that have gained access to all my personal computers, (both old and recently purchased) phones, and even random computers I use to simply get ...
2
votes
1answer
54 views

How do you back up cardholder data remotely without a network connection?

In the PCI DSS version 3 it says: 1.3.3 Do not allow any direct connections inbound or outbound for traffic between the Internet and the cardholder data environment. But in the event of hard ...
0
votes
1answer
44 views

Web browser initiating connection on non-standard ports. Should it be blocked?

I am doing some egress monitoring on my computer. Once in every few days, I would find some strange connections being logged, which I believe is initiated by the web browser through a related but not ...
1
vote
1answer
32 views

How to check whether firewall allows traffic on specific port but not listening on the port [closed]

I have client / server and there is a firewall between them.The server is listening on a port and I want to check if this port is allowed by the firewall. I can only know the ports that the machine ...
-4
votes
1answer
50 views

What are the ways to block all BitTorrent clients from accessing my router? [closed]

What are all the values need to be entered in the source and destination IP address and Subnet mask in order to block the bit torrent file exchange.. i.e. blocking torrenting My router's filtering ...
1
vote
2answers
102 views

Which encryption technique should be used for cloud computing data transfer?

I want to setup my application for cloud computing for Software as a Service. There is going to be a lot of data transfer between my server and client, to and fro. The technique I have envisaged is: ...
3
votes
3answers
193 views

Can firewalls get affected by the traffic they process

Does such attack exist? Forgive my wild imagination but is it possible for a hacker to pretend/try to communicate with a service on the server and when the firewall examines the traffic it get's ...
2
votes
1answer
89 views

Docker port forwarding exposure

I try docker with a simple webapp : docker run -d -v $(pwd):/app -p 8080:80 image_name I have docker listen on 8080: tcp6 0 0 :::8080 :::* LISTEN ...
1
vote
1answer
57 views

Is it possible to track the email sent via BCC List using firewall or network security software?

I want to know whether is it possible to know the conversation/email sent via BCC can be identified by admin in some corporate companies? I have heard that email sent from BCC cannot be identified, ...
0
votes
1answer
64 views

internal proxy server vs DMZ proxy server

What would be reason for placing a proxy server in a Demilitarized Zone (DMZ)? I understand that a DMZ is a separate network to your internal network (lies inbetween internal network and firewall). I ...
0
votes
1answer
29 views

NAT separate firewall or other security tools

It's a conceptual question: Suppose i want to separate NAT and firewall, can it help to my security? INTERNET >>>> NAT >>>> Firewall >>> MyNetwork
1
vote
2answers
129 views

How do proxy servers protect their SSL certificates?

Suppose that there is a http proxy server outside the firewall of an organization hosting a web server. All client connections to the web server happen through this proxy. The client negotiates SSL ...
1
vote
5answers
76 views

Firewall rules by URL

is there a solution to create FW rules by URL instead of IP for inbound traffic? For example a.example.com and b.example.com are the same IP on the DNS, but they are different sites, is there a ...
0
votes
2answers
106 views

Is it not safe to open MySQL's port to the internet?

The consensus on this Server Fault question seems to be that opening port 3306 for MySQL is more dangerous than using an SSH tunnel to access MySQL. I would think that with strong credentials you ...
1
vote
2answers
91 views

How does Network Address Translation (NAT) increase firewall effectiveness

Truth or bald-faced lie: the cheap $50 router you can pick up at your local electronics store for your home broadband Internet connection is actually a pretty effective firewall. Why or why not? How ...
2
votes
1answer
355 views

Is it safe to disable connection tracking in iptables?

While reading about NOTRACK target of raw table in iptables, I encountered an article suggesting that for certain traffic you could (or even should) disable connection tracking. The two examples were: ...
0
votes
1answer
102 views

Is a firewall an access control list?

I want to know if a firewall is considered an access control list (ACL). I know there are other types of ACLs, but am specifically interested in knowing if a firewall is an ACL. Edit: It appears ...
2
votes
2answers
330 views

How to block network scans with pfsense?

I am using pfsense as firewall, and I would like to know how I can stop network scans from enumerating open services and ports. Thanks
4
votes
1answer
78 views

DMZ Firewall settings

I am involved in project where I have to install a new server for a new application to a preexisting production network. The new server shall sit in the DMZ and two controllers will sit on the ...
0
votes
2answers
119 views

Securing a Windows PC

Currently I have an "Antivirus" and Anti Malware software installed. In addition I closed all remote assistance and unused port rules on my firewall. I'd really like to get a complete as possible ...
0
votes
0answers
28 views

Is it possible to covertly tunnel data using L3DSR? (or any other TCP or IP layer hack)

I asked this question on ServerFault regarding how a Netscaler embeds low level data in a TCP packet, round-trips it, and then uses that data to loadbalance the user. Similar to DNS Tunneling, I ...
31
votes
5answers
6k views

Are two firewalls better than one?

Let's say that our first firewall have some vulnerability and malicious person is able to exploit it. If there's second firewall after it, she should be able to stop the attack, right? Also what will ...
0
votes
1answer
44 views

ESET detected incoming connection to Rundll32

My ESET Smart Security 7 detected incoming connection from an external computer, since Rundll32 can be run by any programs on my computer and I don't know which program is doing this, so I am ...
0
votes
1answer
112 views

Firewall hole punching [closed]

I'm interested in doing my thesis on Firewall hole punching. Hole Punching: A way to exploit NAT to open a connection TCP or UDP between a Client and a Server. What I'm looking for is a reason this ...
1
vote
2answers
176 views

Do I need a hardware firewall even if I have Internet security software?

I have Kaspersky Internet Security 2010 installed on my Win7 computer. I assume it gives me enough protection for a software firewall(port security,tracking tcp,udp traffic etc.) Do I still need a ...
-1
votes
2answers
638 views

VPN blocked ports problem

I use VPN quite often in public places where I don't want anyone to read my web traffic. However, some public places have firewalls that block ports required to establish a VPN connection (I usually ...
1
vote
2answers
204 views

How to prevent attacks to server

I have 3 CentOS server configured for my applications. Recently I recognized that there is so many attacks to my servers. I have so many logs about attempt to login to my servers using sshd from ...
-1
votes
2answers
58 views

Intrusion detection system and firewalling

I have a website and hosted some data and MySQL files on it. Is it possible for me to install an intrusion detection system on it, or can IDSs only be installed on my internal network where I have a ...
1
vote
5answers
137 views

Do firewalls always run in userspace?

There are many Firewall solutions for the world on different operating systems: iptables, pf, ipfw. My question is: Does the firewalls run in kernel-space or all of them runs in user-space? (in ...
2
votes
1answer
270 views

How can the Google web crawler bypass portals?

This is a situation that I have encountered on a number of occasions. I will conduct a web search in Google, a link to a file (.pdf for example) will take you to that file on the server. It opens up ...
0
votes
0answers
70 views

How should I configure my Tor-dedicated firewall for optimum security?

I'm setting up a Tor-based isolating proxy using the 'Anonymizing Middlebox' iptables rules specified here: https://trac.torproject.org/projects/tor/wiki/doc/TransparentProxy i.e. iptables -t nat ...
0
votes
0answers
28 views

Carry out an attack on port 80 while only 20 is allowed [duplicate]

There is a question bugging me a after reading on network security. Theoretical situation: there is a packet-filtering firewal which only accepts tcp / ip communication with destination port 22 on a ...
0
votes
1answer
58 views

If I port scan a server on the outside of a firewall will this also tell me the ports the firewall is blocking?

Theoretically I was thinking a firewall inspects the TCP header and looks at the destination port and discards/forwards based on its firewall rules. So could I port scan an external server to the ...
0
votes
0answers
120 views

OpenVPN and firewall configuration in LuCI

I'm trying to find the best (most secure) configuration for the firewall in OpenWRT. I'm using LuCi to configure all the stuff. I have successfully created a VPN (OpenVPN). It is supposed the best ...
0
votes
1answer
162 views

Foreign MRT.exe?

I was managing my firewall using AVG and I noticed this was allowed: I have north american locale, and sometimes Japanese locality(?), and that is not Japanese. It is getting through my firewall, ...
0
votes
1answer
622 views

how to bypass windows xp firewall with nmap

I'm scanning a Windows XP in a virtualized environment. I use all of needed arguments to bypass its firewall but it doesn't answer: nmap -e eth0 -Pn --data-length 5 --badsum -g 80 -S 192.168.1.103 -f ...
2
votes
1answer
134 views

ASA5505 DMZ issue

I have ASA5505 , connected to the WAN on port 0 (called Vlan2), and connected to my development LAN on port 7 (Called Vlan1). I want to add DMZ, and I connected switch and servers to port 3, and ...
1
vote
2answers
48 views

Does it make sense to log accepted traffic on firewall?

Assuming a firewall is properly setup, only allowing determined traffic and dropping everything else, what relevant information (if any) could I get from the log of the accepted rules? From the ...
0
votes
1answer
130 views

Finding the firewall port that filters internet traffic [closed]

In my office, we have static IP's for each system. All the internet traffic from our systems are filtered with a Fortiguard firewall. Is it the default gateway where the firewall is installed? How can ...
1
vote
4answers
98 views

Is it possible to block specific users that connect to the internet behind of same gateway with NAT?

Assume there are two internet users (A and B) that connect to the internet from the same gateway by using NAT. That means they use same IP address while passing through our firewall. Now assume we ...
1
vote
1answer
96 views

Allow loopback in Iptables?

I'm trying to write Iptables rules for a small web server. Almost every source I've encountered recommends to allow loopback access to the web server, but doesn't explain why this is necessary. ...
3
votes
4answers
209 views

Find out what Linux software is trying to phone home

I have seen some suspicious outbound communications blocked on my VPS, which hosts a small experimental Web site, and want to find out which application is making the attempt. The server is running ...
0
votes
1answer
107 views

Would encryption bypass some firewall rules?

Would an encrypted connection be able to bypass a firewall? A firewall is working on layer 1-4 of OSI model, the encryption and decryption is done in presentation layer (layer 7 of the OSI model). Can ...