Skip to main content

Secure Network Architecture Desing

Few days back I was going through an article on "Managing Network Security". Although it was a bit technical, it presented some fundamental idea about designing secure network architecture of an organization. I just picked up few points from the article easy-to-grasp, left the detailed and technical ones.
Design a secure network architecture:

1. Make sure hosts are not permitted to access the Internet directly. They should access
it through content filtering proxies capable of scanning the packets for malicious code. If
they need to be connected by a NAT rule on the firewall, ensure that the necessary network
and security controls (such as desktop firewall, antivirus and antispyware tools) are
present on the host.

2. All emails should pass through a secure mail gateway that is capable of filtering email threats.

3. Implement strong authentication for accessing networked resources.

4. Host hardening lowers the chances of system compromise or exploitation. Stick to best
practices of system installation, followed by hardening and conducting of regular vulnerability
scans. Hardening hosts and network devices directly after installation considerably reduces the attack surface.

5. If your organization uses wireless as a network connectivity option, ensure that proper
security controls are placed to safeguard the flowing of data through a wireless network.
Some of the security measures to be taken are:
a) Secure the wireless access via VPN tunnels or strong encryptions like WPA2.
b) Wireless access points should be hardened and endpoint security measures should be taken.
c) Implement wireless IPS and rogue device detection techniques.

6. Implement a strong password policy in your organization to safeguard online accounts
against password attacks such as brute force, dictionary or hybrid password attacks.

7. Use automated tools to gather network information on a regular basis and analyze them. Create the latest network map based on the information and a list of assets belonging
to your organization. This assists in the detection of rogue devices on wired or wireless
networks. Maintain and update the switch port, router port configuration document. Keep
unused ports disabled on all network points.

8. Use a Security Information and Event Management tool to obtain meaningful security
logs and events correlations. SIEM/SIM tools assist in infrastructure security by providing
important logs to centralized security server and correlate them at that point. It helps IT
security operations personnel be more effective in responding to external and internal

These points figure out an ideal architecture of an oragnization or how it should be.


Popular posts from this blog

File Upload through Null Byte Injection

Sometimes, during file upload we come across situation wherein there would be check on the file extension at the client side as well as server side too. If the application does allow only .jpeg extension to be uploaded, the client side java script checks for the extension of the file before passing the request. We all know that how easily this can be defeated.
Some applications, checks for the extension at the server side also. That's not easy to bypass. However there are some ways with which it still can be bypassed. Most of server side scripts are written in high level languages such as Php, Java etc who still use some C/C++ libraries to read the file name and contents. That leads to the problem. In C/C++ a line ends with /00 or which is called Null Byte. So whenever the interpreter sees a null byte at the end of the a string, it stops reading thinking it has reached at the end of the string.
This can be used for the bypass. It works for many servers, specially php servers. Th…

SQL Injection in search field

Earlier I had written about performing SQL injection in search field and how to do a DoS attack and privilege escalation using 'Like' operators. Now another SQLi exploitation I came across recently. That too in the search field. This becomes important as lots of people don't pay much attention on the search forms/ fields in the application. My aim is to show that a search form can also be exploited with SQL Injection. The following queries are based on a real world exploitation. The steps and data are for just illustration purpose only. Suppose, the search form provides the details of users who have accessed the application some time and their login time details etc, we just need to provide their name in the search box provided. All the data were being going as Post request. So, to just fingerprint the database, I provide, 'nil'+'esh' in the search field and it successfully gives me the results. That means the database behind the application is concatenat…

Insecure protocols

Some basic insecure protocols and risk associated with them: