Concerned with software or hardware firewalls

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293 views

Securing my firewall (both dedicated and iptables-based) [closed]

I have an ASA-5510, but I also intend to maintain strict IP tables on my server (Ubuntu 12.04.2), so that there are two layers of "protection". My iptables look like this: *filter # Allows all ...
-3
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1answer
341 views

Web GUI for Snort + ModSecurity [closed]

I'm trying to find a suitable (or easily modifiable) web GUI for snort + modsecurity logs. As far as I know, Splunk can do that by installing the snort and modsecurity plugins. Is there any other ...
4
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2answers
487 views

Can a firewall tamper with email attachments?

I am using Thunderbird as an email client for managing my different email accounts. Yesterday my friend sent me an email with a PDF attachment. Today when I tried to open the attachment I get the ...
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2answers
1k views

What's the difference between an application-level and circuit-level gateway?

From Wikipedia, I understand that circuit level gateways look at TCP handshakes to filter illegitimate traffic and that application level gateways somehow filter application specific traffic. But I ...
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1answer
235 views

Whats a secure firewall rules using UFW?

On my Ubuntu server I have these services running: netstat -tlnp Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program ...
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4answers
876 views

HTTPS firewall rule

Setting up Firewall rule for HTTPS websites on basic stateless packet filter firewall This seems like a stupid question, but how do I set up a firewall rule to allow HTTPS on a basic packet filter ...
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2answers
265 views

How does a firewall help to protect a server?

Since a potential attacker will exploit the services that are already open to public by firewall rules, how will a firewall help to protect my server from attackers?
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3answers
2k views

Securing a network attached storage on the internet

I recently purchased a network attached storage for personal file storage and would like my family members to store files on the device from their computers as a remote backup. I'd like to secure ...
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3answers
3k views

What is the difference between a Gateway and a Firewall? [closed]

What is the difference between a Gateway and a Firewall and how do they relate to one another? I am a developer trying to get a general understanding of network security.
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3answers
263 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 ...
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2answers
544 views

Allow embedded videos while keeping youtube blocked [closed]

Our organization has launched a training program for employees. the hosting server(internal), has YouTube videos embedded. we have YouTube blocked, and employees access the internet via proxy. How can ...
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2answers
228 views

Remote File Injection in ARGS blocking form updating database

I am getting a page forbidden because mod_security blocks it with Remote File Injection in ARGS rule. How do I stop this apart from not including URLs in the form fields or removing the http:// ...
2
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2answers
219 views

Barracuda antispam access to active directory in dmz : opening port or not?

I have a Barracuda Antispam unit and look to use recipient validation with active directory to stop sending NDRs (non-delivery reports) when we are being spammed. What I see on the web is people ...
5
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1answer
843 views

How to use NMap to portscan a SonicWall that is blocking all attemtps?

It seems that SonicWall is blocking attemtps to scan its ports. I know it has some ports open, like 443, because if I access using the browser I get a web site. But when I try to use NMap I can't see ...
-1
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1answer
588 views

How to find IP Addresses that have been attacking my Computer Ports ? [closed]

I am a newbie at Info Sec, and wanted to know which IP addresses are sources of attack traffic. Can I also find out which ports are being attacked? Can this information be found in windows firewall? ...
2
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0answers
48 views

Could you attack a port without knowing what service was listening? [duplicate]

A lot of discussion I see suggests that changing default ports for services is just "security by obscurity" and is easily defeated by scanning for open ports. My question is this, though, if the ...
1
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1answer
157 views

Are there any cross platform firewall solutions with a central management platform?

Currently I have a bunch of servers scattered across a few different providers e.g. EC2, rackspace. Some boxes are Linux and some are Windows. Currently I'm finding the administration of the ...
6
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3answers
769 views

TCP Sequence Prediction and it's prominence in modern systems/networks

I have a question regarding your experience of TCP Sequence Prediction that I am hoping someone could help with. I am aware of how TCP Sequence Prediction works and how the connection can be hijacked ...
4
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1answer
292 views

Exploited by newbie3viLc063s

My debian server got exploited by some scriptiekiddie who used Newbie3viLc063 http://pastebin.com/jma8JRG1 . Scriptkiddie uploaded logo_php.png to my server (My permissions sucked :s) and he did run ...
6
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2answers
46k views

What are the TCP/UDP ports used by torrent applications?

I want to block torrent traffic on my network because it is utilizing too much bandwidth and disrupted my network traffic. What port range should I use and what protocol TCP or UDP?
3
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1answer
97 views

SYN scan, determining scan vs large file upload

In a system attempting to detect SYN scans, one technique is to analyze the rate of change of (network packets sent from victim host per second). Processes such as uploading a large file would not be ...
5
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1answer
1k views

How to whitelist an Amazon ELB in a(ny) firewall?

We have a customer with a very locked-down network. Any outbound connections require whitelisting of the port and IP address. However, we are running our system behind an Amazon Elastic Load Balancer ...
3
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1answer
103 views

Why guest's connections can pass host's firewall?

I've been wondering about this. Assume a host with a strong firewall setup (for example only allowing port 80). That host has some virtual machines without firewall. Why the connections made on ...
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3answers
143 views

State before getting whitelisted?

There is a data flow of incoming files (from untrusted, external sources), that get whitelisted by a kind of application layer firewall. Is there a common name for the state of the files before they ...
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4answers
9k views

How are spoofed packets detected?

My assumption: When a firewall is configured to drop spoofed packets, it tries to ping (not necessarily ICMP) the source IP and sees if it belongs to a real host or if it's up, and if not, it drops ...
2
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1answer
213 views

Normalizing Windows Advanced Firewall rules

How can I best normalize our Windows Advanced Firewall rules while implementing network segmentation? I want them to be as clear and concise as possible for audit purposes. What few examples I've seen ...
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1answer
1k views

icmp packets not able to reach the firewall despite of adding a specific rule, why?

I am using iptables to allow the icmp traffic in/out of my host. Please find below are the entries from my firewall (linux based):- [root@localhost ~]# iptables -L Chain INPUT (policy DROP) target ...
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3answers
2k views

Is it really better to use port 80 or 443 for outgoing traffic in order to bypass user firewall?

I recently created a reverse connection shell in C#. I tested it with some computers and I noticed that some computers connected back correctly and I established connection with them but another ...
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2answers
2k views

What justification is there for Comcast to block SMTP port 25 outbound from residential service?

Within the last week, Comcast seems to have started blocking port 25 outbound from their residential internet service. I can sort of understand why they might justify blocking it inbound as perhaps ...
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3answers
831 views

Best practices for firewall hardware

I'm planning to implement a linux based firewall/router with at least 6 x 1Gb NIC's (network with ~300 computers/server with >=8 VLANs) Can anybody recommend hardware best practices (reference to ...
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1answer
2k views

Websocket implication for firewalls

(I've read several questions here about websocket but apparently there's no websocket tag) If I understand correctly websockets are using TCP trafic over port 80. What are the implication, if any, ...
5
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2answers
342 views

Is this a DNS attack?

The following graph shows the UDP DNS queries/sec (blue) and DNS responses/sec (red) of traffic passing a router over the preiod of 4 days. DNS query is a DNS packet with query/response flag set to 0 ...
3
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1answer
207 views

Blacklisting during a penetration test?

So i had a debate recently where one of my colleagues believed that by launching a penetration test (one requested by our clients) from our one of our IP's we could potentially get that IP/all IP's in ...
0
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1answer
72 views

Situations that a firewall should use rule for all packets

When should a "match all packets" rule be used (instead of chain policy)? I think that this should be used in real time applications like audio streaming or video broadcasting. Are there other ...
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1answer
189 views

Packet-filtering firewall evasion (Scanning)

Context I'm very familiar with different applications of scanning tools (. . . and you can use -mtu to specify the size of the fragments in nmap . . .) but every piece of information I read about ...
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2answers
2k views

What is more risky? Database Server in DMZ or Trusted Network?

Hoping this is not a dupe of any of the related database / DMZ questions, but I don't think any of them answered my question sufficiently. Assume the following A web server is being used for ...
3
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2answers
196 views

How to red team against firewalled architecture?

Prior Knowledge I understand the types and differences between firewalls. I have (what I believe to be) a relatively good mental model of a firewall. I understand routing, iptables, signature ...
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1answer
225 views

What are the basic implementations that make a network secure from the inside\outside?

Would you consider the following to be "basic hardening items" for network equipment and servers? VLANs Access Control (such as NTFS permissions) Patch Management System Host Firewall Anti-Virus ...
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3answers
8k 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 ...
3
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3answers
1k views

why blocking incoming traffic does not block chatting or VOIP

I just recently blocked all incoming traffic(all local ports and all external ips) in my windows 7 firewall and I understand that will not stop me from accessing websites as browsing needs outbound ...
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2answers
204 views

Firewall on a VM

I know I could use a software firewall on the guest to achieve a situation similar to this, but is there a way to emulate a firewall (protecting multiple Guests) between a host and guests on a ...
6
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2answers
145 views

Are temporary blocks sufficient response to network probes?

We have the option of using an automatic blocking feature of our firewall to temporarily block the source IPs of network probes. It is fast and automatic, and it expires after a set amount of time. ...
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4answers
645 views

Connections through Firewalls explained

I'm looking for a good explanation of how connections work through firewalls. I've got the idea of packaging(encapsulating) some protocol inside another one as its payload when tunneling. But what I ...
3
votes
1answer
257 views

HTTPS form submissions are blocked on corporate networks

We have an HTML form which is submitted via HTTPS. We've noticed that when the form is submitted on a home network, it seems to go through just fine. However, when the form is submitted on certain ...
2
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1answer
93 views

Quick Security Mitigations to Impending attacks

Suppose you are the sysadmin, and you know of an impending attack that just started or about to start soon. You can either wait it out, or try a few tricks and quick mitigation to fend off attackers ...
2
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1answer
568 views

Incoming Packet From Source Port 80

I'm sure no daemon or browser is using network resources, but I found incoming packets from Wireshark: 98.126.43.174 source port 80 --TCP--> MyIp destination port 339 [SYN, ACK] 98.126.43.174 ...
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3answers
1k views

Is it necessary to setup a firewall in both PC and router?

If I have the router firewall enabled, is it really necessary to setup iptables in my system? Isn't it a little redundant? For example I add a rule in the router where the PC can't use the port ...
1
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1answer
107 views

Guidelines on out-of-band server management via integrated Lights-out services (iLO, iDRAC etc.)

Several CVEs (CVE-2012-3271, CVE-2011-4158, and earlier) point out vulnerabilities in remote server administration firmware; what are the guidelines on hardening this extremely useful component of ...
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1answer
211 views

Weird issue with Firewall blocking NATed packets

From my SIEM I am seeing that a (we don't own the FW) Cisco ASA is blocking packets destined for the internal network (post NAT), here's what I'm seeing (IP addresses are faked due to security) ...
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2answers
155 views

Blocking executables at the firewall in the enterprise

The infrastructure team in our medium enterprise has requested blocking of all executables at the firewall. We have a firewall which is capable of DLP, so therefore this can be set up fairly easily. ...