Tag: centos

Openvas installation in CentOS 7

What is Openvas?

OpenVAS (Open Vulnerability Assessment System, originally known as GNessUs) is a software framework of several services and tools offering vulnerability scanning and vulnerability management.

All OpenVAS products are free software, and most components are licensed under the GNU General Public License (GPL). Plugins for OpenVAS are written in the Nessus Attack Scripting Language, NASL.

The primary reason to use this scan type is to perform comprehensive security testing of an IP address. It will initially perform a port scan of an IP address to find open services. Once listening services are discovered they are then tested for known vulnerabilities and misconfiguration using a large database (more than 53000 NVT checks). The results are then compiled into a report with detailed information regarding each vulnerability and notable issues discovered.

Once you receive the results of the tests, you will need to check each finding for relevance and possibly false positives. Any confirmed vulnerabilities should be re-mediated to ensure your systems are not at risk.

Vulnerability scans performed from externally hosted servers give you the same perspective as an attacker. This has the advantage of understanding exactly what is exposed on external-facing services.

Step 1: Disable SELinux

sed -i 's/=enforcing/=disabled/' /etc/selinux/config

and reboot the machine.

Step 2:  Install dependencies

yum -y install wget rsync curl net-tools

Step 3: Install OpenVAS repository

install the official repository so that OpenVAS works appropriately in the analysis of vulnerabilities.

wget -q -O - http://www.atomicorp.com/installers/atomic |sh

Step 4: Install OpenVAS

yum -y install openvas

Step 5: Run OpenVAS

Once OpenVAS is installed, we continue to start it by executing the following command:

openvas-setup

Once downloaded it will be necessary to configure the GSAD IP address, Greenbone Security Assistant, which is a web interface to manage system scans.

Step 6: Configure OpenVAS Connectivity

We go to our browser and enter the IP address of the CentOS 7 server where we have installed OpenVAS, and we will see that the following message is displayed:

Openvas dashboard

 

Automatic NVT Updates With Cron

35 1 * * * /usr/sbin/greenbone-nvt-sync > /dev/null
5 0 * * * /usr/sbin/greenbone-scapdata-sync > /dev/null
5 1 * * * /usr/sbin/greenbone-certdata-sync > /dev/null

 

How to install Asterisk on CentOS

In this installment of our How To, we are going to go over on the topic of how to install Asterisk on CentOS. For this we are going to use Asterisk 13 and CentOS 7 minimal version. But, instructions will mostly be similar to other versions of Asterisk and CentOS.

As a first step you need to download latest asterisk on to your machine. For this you need wget tool. As we are using minimal flavor of CentOS even wget tool is not available on fresh install. Run the following command to install wget.

Once, wget is installed successfully, run the following command to download asterisk.

Extract downloaded asterisk tar ball

Install the following dependencies

Once, all the above dependencies are installed. You can now run the following command to enable or disable modules of your choice.

After you are done with the menuselect screen, run the following command to compile and install asterisk

That’s it now you have asterisk installed successfully on your you machine. Run, the following command to start asterisk

Now, you should see asterisk console saying “Asterisk Ready”. Instead, if you encounter the following error

Don’t worry, just run the following command and start asterisk again after that.