Tagged Questions

Concerned with software or hardware firewalls

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0
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2answers
397 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
120 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
1k 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: ...
1
vote
1answer
148 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
793 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
101 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
130 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
39 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
64 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
142 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
202 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
2k 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
469 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
60 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
191 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
318 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
100 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
66 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
193 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
217 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
894 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
2answers
225 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
139 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
106 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
165 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
270 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
114 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 ...
0
votes
3answers
134 views

How source port field in firewall rule is used

Some firewalls (like the first figure in 13.1.4 in http://doc.m0n0.ch/handbook/examples.html) allow user to specify source port in a firewall rules. But in a TCP connection, the source port is ...
1
vote
2answers
192 views

What security does an ISP provide for its customers?

I've heard that ISPs provide some kind of protection; using NAT and firewalls, to prevent hackers from using tools such as nmap to attack customers from over the Internet. What other technologies are ...
0
votes
2answers
422 views

Could a router protect our network or need we use an hardware firewall?

I am at a small firm (12 PC on the internal network). We use this network architecture now: Internet(Modem) --> Router --> Firewall --> Switch -- > Internal Network (clients PCs) ...
1
vote
1answer
1k views

Windows Firewall netsh equivalent of iptables u32 module

I have looked everywhere and I can't seem to find a netsh equivalent of the u32 module for iptables. I want to create a rule to Drop a packet that starts with a specific set of bytes. Similar to: # ...
3
votes
2answers
863 views

Blocking incoming traffic from privileged port (< 1024) to mitigate DNS DDos Amplification attacks

Hope someone can clarify. As I understand, in a DNS DDos Amplification attacks Multiple DNS queries are sent to a vulnerable name server with the source IP spoofed to that of the target server. The ...
0
votes
1answer
89 views

Sky Broadband Shield

I was just wondering the implication's to Sky's new revelation of a so called 'shield'. Is this actually even a security feature or just a advertisement stunt for Captain America. I can find very ...
0
votes
1answer
624 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 ...
4
votes
3answers
378 views

Can a web server be secured with just a firewall?

I'm about to go online with my first web site, it is a small project hosted on a regular home PC running Windows 7. I want to keep the software footprint at minimum, so it only contains the operating ...
1
vote
0answers
50 views

API deployment infrastructure

We are going to deploy our service, it's drupal based with some additional REST APIs. The drupal servers will be (loadbalanced) put in the DMZ. We think to deploy the REST APIs on an app server in ...
1
vote
2answers
72 views

Is rolling my own firewall on top of my normal firewall dangerous?

I'm thinking about playing with/learning about firewalls. It is easier for me to learn by building, so why not build a firewall? If I run it alongside my normal firewall, I'd get the normal ...
1
vote
4answers
182 views

Comprehensive audit of firewall - is Internet truly not accessible?

We have many Linux servers in several co-locations over the world. By design, these machines generally should not be able to access the Internet. Depending on location and role, some sites may have ...
2
votes
1answer
346 views

How to configure Suricata to not interfere with virtual machine

I'm currently planning on setting up Suricata as a firewall on my laptop. I'm wondering however if it's possible to set Suricata to not interfere with traffic to and from specific virtual machines ...
0
votes
1answer
151 views

Is it a bad idea to use port forwarding as a long-term access strategy?

We are deploying multiple copies of the same system (some devices behind a gateway with NAT), and we need to have continued access for some of those devices. Right now our strategy is to have a set of ...
1
vote
2answers
376 views

SSH Security allowing only certain users to connect to the server [closed]

I have set up a remote ssh server on the cloud. I am newb at these things and have managed to bypass the required firewall using SSH. Now I plan on giving the access to only 2 more friends of mine so ...
0
votes
4answers
140 views

How to secure my website's FTP?

When I opened ftp command prompt and typed open mydomain.com, it gave me the following and I think that this is a security vulnerable. connected to mydomain.com. 220----- Welcome to Pure-FTPd ...
2
votes
1answer
309 views

IPS/IDS and Firewall Solution(s) to a Small Office

I was tasked with implementing a network security solution for a small real estate agency. They are a typical old-school mom and pops shop, about 15 employees with basic file sharing, printing, and ...
0
votes
2answers
1k views

Should I restrict Core Networking firewall rules in Windows server?

I have a server that I want to restrict access to by allowing only one IP address to be able to connect to it through desktop and make http request through port 80. Now in my firewall I only have ...
0
votes
1answer
219 views

Application Server <-> Database Firewall [closed]

What threats can a firewall between an application server and a database server mitigate that would not otherwise be mitigated when both the database server and application server are behind the same ...
1
vote
0answers
225 views

Proxy via pfSense and exclusions for DNS

I have posted this to NetworkEngineering.SE, as that seems the more suitable audience for this question. I will leave this question open here but am happy to see it closed. I just did not want to ...
1
vote
2answers
317 views

VPN Client - Addtional Security Layer or a Useless Feature

I have a corporate web portal which is used for staff collaboration including a web-based mail interface connected to MySQL Database, corporate calendar, file storage, customer contacts data with ...