Thursday, May 17, 2007

Network security - Firewall setting

You probably know that you need firewall security; in fact, you may even already have a firewall management program in place. But what exactly is firewall security, and what does firewall management entail?


The word firewall originally referred literally to a wall, which was constructed to halt the spread of a fire. In the world of computer firewall protection, a firewall refers to a network device which blocks certain kinds of network traffic, forming a barrier between a trusted and an untrusted network. It is analogous to a physical firewall in the sense that firewall security attempts to block the spread of computer attacks.


How Does Firewall Management Work?

A firewall management program can be configured one of two basic ways:

* A default-deny policy. The firewall administrator lists the allowed network services, and everything else is denied.
* A default-allow policy. The firewall administrator lists network services which are not allowed, and everything else is accepted.

A default-deny approach to firewall security is by far the more secure, but due to the difficulty in configuring and managing a network in that fashion, many networks instead use the default-allow approach. Let's assume for the moment that your firewall management program utilizes a default-deny policy, and you only have certain services enabled that you want people to be able to use from the Internet. For example, you have a web server which you want the general public to be able to access. What happens next depends on what kind of firewall security you have.

Below is a firewall security script, has been tested with Kerio Personal Firewall, may this rule can accepted to others firewall:

LSA Shell (lsass.exe) -> Ask - Permit - Ask - Ask
Windows NT Logon Application (winlogon.exe) -> Ask - Permit - Ask - Ask (log)
Userinit Logon Application (userinit.exe) -> Ask - Permit - Ask - Ask
Generic Host Process (svchost.exe) -> Ask - Permit - Ask - Ask (log)
Microsoft File & Printer Sharing -> Deny All (For LAN can be: Ask - Permit - Ask - Ask)
Any Other Application -> Deny - Ask - Deny - Ask (log & alert). invisible mode
Internet Browser Application -> ask - deny - deny - permit (log)
Kaspersky AntiVirus/ Kaspersky Internet Security -> ask - deny - deny - permit (log)
FTP Manager Application -> permit - permit - permit - permit (log & alert)
Yahoo Messenger -> deny - ask - deny - permit (log & alert)


Below is the rule script for Filter packet in Ferio Firewall or Tiny firewall and may can accepted to others firewall:

RULE 1
Description: ISP Domain Name Server Any App UDP
Protocol: UDP
Direction: Both
Local Port: Any
Local App.: Any
Remote Address Type: Single
Host address: IP number (Your ISP DNS server)
Port type: Single
Port number: 53
Action PERMIT

RULE 2
Description: Other DNS
Protocol: TCP and UDP
Direction: Both
Local Port: Any
Local App.: Any
Remote Address Type: Any
Port type: Single
Port number: 53
Action DENY

RULE 3
Description: Back Orifice Block (Logged)
Protocol: TCP and UDP
Direction: Incoming
Port type: List of Ports
Local App.: Any
List of Ports: 54320,54321,31337
Remote Address Type: Any
Port type: Any
Action DENY

RULE 4
Description: Netbus Block (Logged)
Protocol: TCP
Direction: Incoming
Port type: List of Ports
Local App.: Any
List of Ports: 12456,12345,12346,20034
Remote Address Type: Any
Port type: Any
Action DENY

RULE 5
Description: RPCSS (Logged)
Protocol: UDP
Direction: Incoming
Port type: Single port
Local App.: Any
Port number: 135
Remote Address Type: Any
Port type: Any
Action DENY

RULE 6
Description: Block Low Trojan Ports TCP UDP (Notify)
Protocol: TCP and UDP
Direction: Both
Port type: Port/range
Local App.: Any
First port number: 1
Last port number: 79
Remote Address Type: Any
Port type: Any
Action DENY

RULE 7
Description: Block High Trojan Ports TCP UDP (Notify)
Protocol: TCP and UDP
Direction: Both
Port type: Port/range
Local App.: Any
First port number: 5000
Last port number: 65535
Remote Address Type: Any
Port type: Any
Action DENY

RULE 8
Description: Block Outbound Unauthorized Apps TCP UDP
(Notify)
Protocol: TCP and UDP
Direction: Outgoing
Port type: Any
Local App.: Any
Remote Address Type: Any
Port type: Any
Action DENY
Nb: Kaspersky Antivirus 6 & Kaspersky Internet Security 6 usage, the remote port address choose Any)

RULE 9

Description: Block Inbound Unknown Apps TCP UDP
(Notify)
Protocol: TCP and UDP
Direction: Incoming
Port type: Any
Local App.: Any
Remote Address Type: Any
Port type: Any
Action DENY

RULE 10

Description: Block ICMP (Logged)
Protocol: ICMP
Direction: Both
ICMP Type: Echo Reply, Destination Unreachable, Source
Quench, Redirect,
Echo, Time Exceeded, Parameter Prob, Time Stamp, Time
StampReply, Info
Request, Info Reply, Address, Address Reply, Router
Advertisement, Router
Solicitation (ALL)
Remote Endpoint: Any
Action DENY

RULE 11

Description: In Block Ping and TraceRoute ICMP
(Notify)
Protocol: ICMP
Direction: Incoming
ICMP Type: Echo
Remote Endpoint: Any
Action DENY

RULE 12

Description: Out Block Ping and Trace Route ICMP
(Notify)
Protocol: ICMP
Direction: Outgoing
ICMP Type: Echo Reply, Destination Unreachable, Time
Exceeded
Remote Endpoint: Any
Action DENY

RULE 13

Description: Block Common Ports (Logged)
Protocol: TCP and UDP
Direction: Incoming
Port type: List of Ports
Local App.: Any
List of Ports:
113,79,21,80,443,8080,143,110,25,23,22,42,53,98
Remote Address Type: Any
Port type: Any
Action DENY

RULE 14
Description: Loopback
Protocol: TCP and UDP
Direction: Both
Local Port: Any
Local App.: Any
Remote Address Type: Single
Host address: 127.0.0.1
Port type: Any
Action PERMIT

RULE 15
Description: Block Inbound NetBIOS TCP UDP (Notify)
Protocol: TCP and UDP
Direction: Incoming
Port type: Port/Range
First Port: 137
Last Port: 139
Local App.: Any
Remote Address Type: Any
Port type: Any
Action DENY

RULE 16
Description: Block Outbound NetBIOS TCP UDP (Notify)
Protocol: TCP and UDP
Direction: Outgoing
Local Port: Any
Local App.: Any
Remote Address Type: Any
Port type: Port/Range
First Port: 137
Last Port: 139
Action DENY

RULE 17

Description: Bootpc (Logged)
Protocol: TCP and UDP
Direction: Incoming
Port type: Single port
Local App.: Any
Port number: 68
Remote Address Type: Any
Port type: Any
Action DENY

RULE 18

Description: Out Needed To Ping And TraceRoute Others
Protocol: ICMP
Direction: Outgoing
ICMP Type: Echo
Remote Endpoint: Any
Action PERMIT

RULE 19

Description: In Needed To Ping And TraceRoute Others
Protocol: ICMP
Direction: Incoming
ICMP Type: Echo Reply, Destination Unreachable, Time
Exceeded
Remote Endpoint: Any
Action PERMIT

RULE 20

Description: Internet Explorer-Web browsing (logged)
Protocol: TCP
Direction: Outgoing
Port type: Any
Local App.: Only selected below => iexplore.exe
Remote Address Type: Any
Port type: Any
List of ports: Any
Action PERMIT

RULE 21

Description: Outlook Express
Protocol: TCP
Direction: Outgoing
Port type: Any
Local App.: Only selected below => msimn.exe
Remote Address Type: Any
Port type: List of ports
List of ports: 25,110,119,143
Action PERMIT

RULE 22
Description: Yahoo Messenger
Protocol: TCP
Direction: Outgoing
Port Type: Any
Local App.: Only selected below => yahoomessenger.exe
Remote Address Type: Any
Port Type: List of ports
List of ports: 443,80,5050
Action PERMIT

RULE 23

Description: Yahoo Messenger
Protocol: UDP
Direction: Outgoing
Port Type: Any
Local App.: Only selected below => yahoomessenger.exe
Remote Address Type: Any
Port Type: single
List of ports: 3478
Action PERMIT

RULE 24
Description: Download Manager (logged)
Protocol: TCP
Direction: Outgoing
Port Type: Any
Local App.: Only selected below => (your download manager file)
Remote Address Type: Any
Port Type: List of ports
List of ports: 80,21
Action PERMIT


For filter packet setting on Local Area Network (LAN) can added with below rule script to allow NetBIOS access at specific port:

RULE 15a
Description: Trusted Inbound NetBIOS TCP UDP
Protocol: TCP and UDP
Direction: Incoming
Port type: Port/Range
First Port: 137
Last Port: 139
Local App.: Any
Remote Address Type: Trusted Address Group
Port type: Any
Action PERMIT

RULE 16b

Description: Trusted Outbound NetBIOS TCP UDP
Protocol: TCP and UDP
Direction: Outgoing
Local Port: Any
Local App.: Any
Remote Address Type: Trusted Address Group
Port type: Port/Range
First Port: 137
Last Port: 139
Action PERMIT

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Original Template | by: Elque 2007 | Modify by : Jan Pieter Marbun (June 2007)