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Questions tagged [firewalls]

Concerned with software or hardware firewalls

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2answers
46 views

Security of next generation firewall

In recent years there's been a number of IndieGoGo or KickStarter projects for smart device protection, or next-generation firewalls. Some examples are: Anonabox, Cujo, Dojo, Firewalla, Keezel, ...
1
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2answers
55 views

How does TLS traffic impact firewalls?

If I have an open port on a firewall it means that I can receive traffic on that port. If it's unencrypted I assume that the raw data is just allowed through. If TLS is being used, does firewall ...
5
votes
3answers
465 views

What are the security implications of allowing unlimited size cookies?

Our application firewall blocks requests if it detects a cookie is present with a value greater than 1024 characters in size. Are there any exploits involving large cookies? i.e. How much more ...
0
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1answer
36 views

Network diagram based on Cisco ACL and other firewall rules [on hold]

Are there any tools for automated building network diagram from ACL rules or any other firewall rules?
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0answers
38 views

Is there a risk to block multicast? [on hold]

I'm thinking to block multicast traffic in my firewall, both sending to local multicast and receiving from local multicast. Is there any security risks or possible known problems for doing that? My ...
3
votes
1answer
331 views

Ports Showing Closed/Filtered in Nmap Scans

hopefully this isn't a stupid question.. I am running some nmap scans and I get a list of ports that show closed. Why would they even show in the scan report? Can these be exploited further with other ...
1
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1answer
86 views
3
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3answers
255 views

Web Application Firewall using web app source code analysis

I read this page: Category:OWASP Best Practices: Use of Web Application Firewalls, and I found that WAF cannot generally detect logical attacks. We know each web application has a number of input ...
4
votes
3answers
538 views

The safest way to circumventing Iran's Internet censorship

We usually buy services like VPN, SOCKS, Kerio [Kerio Connect?]... to circumvent Iran's Internet censorship policy. Recently, one of the shops started selling [one of] Kerio's products, for which I do ...
1
vote
1answer
92 views

Why would my firewall be blocking external source and external destination IP's that I dont own?

In my Cisco ASA firewall logs I'm seeing events being blocked with an external source IP and a external destination IP. This is happening in the same event log. An example would be: TCP access ...
3
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1answer
38 views

Providing access to Git repo behind a Firewall using Certs/Keys for Authentication

We have a Git repo sitting behind a firewall. As I see it, there are two ways of authenticating/accessing the Git repo: Add a Reverse HTTP Proxy in the DMZ that communicates with the Git repo. This ...
1
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2answers
111 views

Firewalls vs DMZ

What's the difference between Firewalls and DMZs? These terms seem to overlap at time and I'm not clear on the difference. Maybe a DMZ is achieved using firewalls?
0
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1answer
93 views

Difference(s) between an ACL and a Layer 4 (Stateful) Firewall [closed]

What is the primary difference(s) between an ACL and a Layer 4 (Stateful) Firewall? I'm looking for a basic explanation if possible as I want to build my foundation knowledge. I understand that an ...
7
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1answer
18k views

How do I access a firewall log (Windows 10 w. Windows Defender)

I am going through some event logs (in event viewer), and noticed I can't seem to find any firewall logs. Windows Defender provides the firewall. How do I get to the firewall logs that should be ...
0
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1answer
41 views

Are there any alternative methods for reverse connections that bypass firewalls?

I'm doing a PenTest on a server. I have an RCE vulnerability on it, but when I try to do a reverse connection via netcat, the firewall blocks it. Is there any other methods used for reverse ...
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0answers
50 views

Stopping “phone home” applications in VM with TBB

I have a VM with Linux and the TBB installed on it. What I am trying to do is to make sure that other applications like for example operating system applications cannot "phone home" while I am using ...
-1
votes
1answer
86 views

Detecting and blocking TCP VPN connections that bypasses existing VPN detection software

I help manage a small college campus network and students are not allowed to visit certain sites and download using torrents. Currently I'm able to block UDP VPN connections, but TCP VPN connections ...
2
votes
2answers
176 views

How do the CVE-2018-10562 and CVE-2018-10561 exploits work?

https://www.vpnmentor.com/blog/critical-vulnerability-gpon-router/ Firstly, the use of 'GPON' I find misleading because this vulnerability is to do with the routers and webservers and not the access ...
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0answers
36 views

Windows Firewall blocking local access to SQL Server?

I have an AWS virtual machine running a web application on IIS that connects to a SQL Server database (on the same machine). Recently, I have noticed that there are a plethora of failed login attempts ...
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0answers
6 views

What's wrong with this outbound iptables firewall? [migrated]

I have a mail server which I'd like to secure by only allowing OUTBOUND connections on the various ports it uses. The inbound rules are working fine - they are handled by the VM host. I've not been ...
-1
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0answers
46 views

Is it safe to whitelist 0.0.0.0/0 ports 4172 tcp/udp outbound?

AWS is asking the users to whitelist URLs at firewall level or an entire IP for port 4172. What are the security risks by whitelisting the entire IP range for a specific port at firewall level? What ...
0
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0answers
49 views

Windows Firewall - How do I know that I have completely blocked a program?

I have a specific software that I cannot let out to the internet but it is crucial that it has access to the local network. I can create an inbound and an outbound Block rule for the main application'...
1
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0answers
38 views

OpenAppID with Snort on pfSense [closed]

I'm using OpenAppID with Snort on pfSense, it actually work but when I view some script detector, it just detect by http pattern, which I can replace by using snort rule (with "content" option). So ...
0
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1answer
358 views

Is it advisable to accept STUN server connections?

My firewall reports outgoing connection attempts via com.apple.WebKit.Networking to a number of STUN servers (namely, stun.nas.net, stun.node4.co.uk, stun.voxox.com and stun.wwdl.net). This is ...
0
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1answer
106 views

Difference between a behaviour-based security and traditional firewall?

Difference between a behaviour-based security and traditional firewall? As I have searched the web and honestly cannot find anything about it.
25
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7answers
91k views

How to bypass tcpwrapped with nmap scan

I'd a scan task and I faced following result Host is up (0.032s latency). Scanned at 2012-10-25 16:06:38 AST for 856s PORT STATE SERVICE VERSION 1/tcp open tcpwrapped 3/tcp open ...
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3answers
552 views

Windows firewall blocking of a dynamically generated .exe

If I block application A.exe on my firewall, but it dynamically generates B.exe and runs it automatically. Would B.exe also be blocked on my firewall?
7
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2answers
1k views

I'm having a DDoS attack, my hosting company is not giving me a solution, and I need to know what is hapening

So ok, right now my windows 2003 dedicated server is under attack by some guy who's flooding UDP packets (~90.000 packets/sec) on my 100Mbps server for the last 8 hours. I'm on a shared port, so I'm ...
0
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1answer
24 views

In what situations / with what nodes should a node ping / not ping?

I was recently looking at a network in which the client-machines that accessed a webservice endpoint, but which could not ping the webservice endpoint. And there are other machines that can ping the ...
1
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2answers
5k views

Can a hacker hack into port 80?

We normally say port 80 is firewall friendly. But can a hacker just hack into port 80 via TCP or UDP? Or is Port 80 by default not always open? It waits for the host to initiate a connection via ...
2
votes
3answers
3k views

Large amount of foreign IPs hitting out firewall, is this automated scans or are we under attack?

I just got put in charge of a network. In the logs on our firewall I noticed that we had a large amounts of machines trying to connect to port 53 as well as about a dozen other ports. Are these ...
1
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0answers
57 views

Weak ciphers in TLS VPN

We have a firewall out of our firm network and administrators connect to this firewall by VPN over TLS. Scanning this firewall, the vulnerability scanner get us some warning as the 443 port allow weak ...
3
votes
1answer
62 views

Block Outbound Connections by Country

We want to reduce the number of phishing sites that our users can get to. Would it be useful or more problematic to block outbound connections by geo IP? We already block many inbound connections by ...
0
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1answer
55 views

Can Snort or Suricata *edit* packet on the fly?

I know that they can detect traffic by rules, but can they modify packets on the go? For example, not only detecting HTTP GET but also adding headers to the GET packet. If they can't, is there an ...
3
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3answers
6k views

Is QUIC (Quick UDP Internet Connections) safe to allow through firewall?

Our firewall currently blocks QUIC (UDP 443) traffic which seems to be enabled by default in Google Chrome. Is it safe to allow QUIC or should I wait until it is implemented in all the major browsers? ...
1
vote
1answer
81 views

Fortigate Creating Millions of DNS events to standard domains

I am trying to tune our SIEM and noticed that we are receiving millions of DNS records every day from the same domains. These are: update.microsoft.com swscan.apple.com softwareupdate.vmware.com ...
2
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0answers
33 views

Beginner UFW question about destination any

I'm learning about UFW with a Raspberry Pi and I don't a couple of things when it comes to UFW rules. Can anyone help me suss a couple things out? My first question is about the destination any. If I ...
22
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4answers
79k views

Windows Firewall - how to block inbound for all .exe files in a folder

In Windows Firewall with Advanced Settings I can create a rule which blocks all inbound or outbound traffic for particular program by pointing to its .exe file. The problem is that this program has ...
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0answers
78 views

Filter/Block OpenVPN clients' access to a specific website

As stated in the title I would like to restrict VPN clients' access to specific websites. More specifically, I push the route for 5 websites to the clients via the server config. However, I would ...
0
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2answers
101 views

Why should I bother having a firewall on servers?

In the case of a server, the only applications that are running there are the ones that I've setup, so you don't just have random users downloading & running malware. The only ports that are open ...
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1answer
306 views

Ability to get a MAC address and IPv6 through proxy servers

Now I'm pretty sure I know the answer to this question, but I am just curious to see what the security experts of the world think of this. First a little back story: I was a former member of a ...
23
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7answers
3k views

How can I publish data from a private network without adding a bidirectional link to another network

I was just wondering how I could build a private network where it is physically impossible to gain access from outside but still have the option to publish data to some remote server. As an example: ...
0
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1answer
82 views

Country Blocking

I use a Meraki firewall and want to block outside attack attempts. Is there a list of countries that are known to be malicious? I want to load them into the system and GEO block them. I know that some ...
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1answer
63 views

Types of firewalls to implement to reduce DoS attacks in POS systems

Would you need an internal, external and a host-resident firewall for each POS client?
0
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1answer
111 views

Secure onion router setup [closed]

I would like to setup a Raspberry Pi as an onion router, but I have some questions about it. At home I am using a Fritz!Box to connect to the outer world (to the net of my ISP). Would it make any ...
0
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0answers
92 views

PHP socks proxy with no port opening

let's say i have file apache file access on a webserver, but due to firewall rules etc, i can't connect to ssh and can't open a port. Is there a way to do this exactly this : create a socks proxy on ...
0
votes
1answer
329 views

Why won't ossec block SSH connections when it seems to be configured correctly?

Why won't ossec block connections from another server? I installed ossec version 2.9.3 on Ubuntu 16.04. In the ossec.conf file I have these lines where x.x.x.x is the IP address of a second Linux ...
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1answer
184 views

Differentiating between IKEv2 and OpenVPN Traffic

There is a WiFi network that I regularly use, and it seems to be blocking all VPN traffic other than IKEv2. I tested this by downloading many of the free/freemium VPN apps from the Google Play Store ...
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0answers
12 views

Why Does Windows Server Block ICMP By Default? [duplicate]

I am conducting a OpenVAS vulnerability scan on a Windows Server 2012 box and it came back empty. It turns out that the scanner checks to see if the host is alive by sending it a ping request--if it ...
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0answers
40 views

Distributed network with one host behind dmz and the other without

Context: This a question from my homework assignment. There is a company with two sites A and B. B is behind DMZ (firewall - proxy mail server - firewall) and A is just behind a firewall Network A ...