security Archives

Checking a website's SSL certificate with openssl.

How to install ssl on RHEL 8 / CentOS 8

6 January 2019 by Thomas Sandmann

As interconnected computer networks enter more and more fields of everyday life, cybersecurity is getting louder and louder. We protect our websites, the traffic on our websites, the computers we initiate the traffic from, maybe (part of) the disks our operating system run from, our connection to work, the computers we attach to at work, and so on.

openssl is an essential tool on any recent GNU/Linux distribution if one have to work with various certificates.

In this tutorial we will install (and reinstall) the openssl package, and test it’s functionality by checking a website’s certificate chain with it’s help.

In this tutorial you will learn:

How to install openssl
How to reinstall openssl
How to check a website’s SSL certificate chain with openssl

How to install syslog on RHEL 8 / CentOS 8

31 December 2018 by Thomas Sandmann

The syslog functionality is one of the main tools for a sysadmin. While writing logfiles with events of interest is a common feature of any application, having a system-wide logging functionality means all logs can be handled as one on the system. But syslog does not stop there. With these tool, a sysadmin can centralize log processing in the datacenter by forwarding the incoming events from applications to central logservers, where they can be processed at a large scale.

Centralized logging is an overkill on a home system with a few computers, but already have it’s benefits around a dozen machine. For example, a dozen desktops sending all their logfiles to a central logserver mean they don’t need to store them on the long run, the logs will occupy disk space in the logserver. The admin can check for problems in only one place (possibly by means of automated reports), the logs can be preserved in a safe way by the means of backups, stored more effective by means of heavy compressing, and will not be lost on a client’s failure or user error.

In this tutorial you will learn:

How to install rsyslog package on RHEL 8 / CentOS 8.
How to verify successful install.
How to start, stop and autostart rsyslog service.
How to test syslog functionality with logger.

How to configure firewall in Ubuntu 18.04

18 December 2018 by Sandip Bhowmik

A properly configured firewall is one of the most important aspects of the overall system security. By default Ubuntu comes with a firewall configuration tool called UFW (Uncomplicated Firewall).

UFW is a user-friendly front-end for managing iptables firewall rules and its main goal is to make managing iptables easier or as the name says uncomplicated. Ubuntu’s firewall is designed as an easy way to perform basic firewall tasks without learning iptables. It doesn’t offer all the power of the standard iptables commands, but it’s less complex.

In this tutorial you will learn:

What is UFW and its Overview.
How to Install UFW and Perform Status Check.
How to Use IPv6 with UFW.
UFW Default Policies.
Application Profiles.
How to Allow and Deny Connections.
Firewall Log.
How to Delete UFW Rules.
How to Disable and Reset UFW.

Creating Wordlists with Crunch on Kali Linux

28 September 2018 by Nick Congleton

Introduction

Wordlists are a key part of brute force password attacks. For those readers that aren’t familiar, a brute force password attack is an attack in which an attacker uses a script to repeatedly attempt to log into an account until they receive a positive result. Brute force attacks are fairly overt and can cause a properly configured server to lock out an attacker or their IP.

This is the point of testing the security of log in systems this way. Your server should ban attackers that attempt these attacks, and should report the increased traffic. On the user end, passwords should be more secure. It’s important to understand how the attack is carried out to create and enforce a strong password policy.

Kali Linux comes with a powerful tool for creating wordlists of any length. It’s a simple command line utility called Crunch. It has simple syntax and can easily be adjusted to suit your needs. Beware, though, these lists can be very large and can easily fill an entire hard drive.

Learn Burp Suite on Kali Linux: Part 2

28 September 2018 by Nick Congleton

Introduction

In this second part of the Burp Suite series you will lean how to use the Burp Suite proxy to collect data from requests from your browser. You will explore how an intercepting proxy works and how to read the request and response data collected by Burp Suite.

The third part of the guide will take you through a realistic scenario of how you would use the data collected by the proxy for a real test.

There are more tools built in to Burp Suite that you can use the data that you collect with, but those will be covered in the fourth and final part of the series.

Learn Burp Suite on Kali Linux: Part 3

28 September 2018 by Admin

Introduction

In this third part of the Burp Suite series, you will learn how to actually collect proxied traffic with Burp Suite and use it launch and actual brute force attack. It will run somewhat parallel to our guide on Testing WordPress Logins with Hydra. In this case, though, you will use Burp Suite to gather information on WordPress.

The purpose of this guide is to illustrate how the information gathered by Burp Suite’s proxy can be used to conduct a penetration test. Do Not use this on any machines or networks that you do not own.

For this guide, you will also need Hydra installed. It’s not going to go into depth on how to use Hydra, you can check out our Hydra SSH guide for that. Kali Linux already has Hydra installed by default, so if you’re using Kali, don’t worry. Otherwise, Hydra should be in your distro’s repositories.

Learn Burp Suite on Kali Linux: Part 4

28 September 2018 by Nick Congleton

Introduction

It’s important to remember that Burp Suite is a software suite, and that’s why a whole series was needed to cover even just the basics. Because it is a suite, there are also more tools bundled in that work in conjunction with one another and the proxy that you’re already familiar with. These tools can make testing any number of aspects of a web application much simpler.

This guide isn’t going to go into every tool, and it isn’t going into too much depth. Some of the tools in Burp Suite are only available with the paid version of the suite. Others generally aren’t used as frequently. As a result, some of the more commonly used ones were selected to give you the best practical overview possible.

All of these tools can be found on the top row of tabs in Burp Suite. Like the proxy, many of them has sub-tabs and sub-menus. Feel free to explore before getting into the individual tools.

Use Aircrack-ng To Test Your WiFi Password on Kali Linux

28 September 2018 by Nick Congleton

Objective

Test the security of your WiFi password by attacking it

Distributions

This will work with any Linux distribution, but it’s recommended that you use Kali.

Requirements

A working Linux distribution with a WiFi adapter and root privileges.

Difficulty

Easy

Conventions

# – requires given linux commands to be executed with root privileges either directly as a root user or by use of sudo command
$ – requires given linux commands to be executed as a regular non-privileged user

Introduction

Most people have terrible passwords, and WiFi is no exception. Your WiFi password is your primary line of defense against unwanted access to your network. That access can result in a whole host of other nasty things because an attacker can monitor the traffic on your network and even gain direct access to your computers.

The best way to prevent such an intrusion is to use the same tools an attacker would to test the security of your WiFi password.

Create An Evil Twin Of Your Network With Fluxion on Kali Linux

28 September 2018 by Nick Congleton

Objective

Use Fluxion to create a evil twin access point to steal WiFi login credentials, demonstrating the need for user education.

Distributions

Kali Linux is preferred, but this can be done with any Linux distribution.

Requirements

A working Linux install with root privileges and two wireless network adapters.

Difficulty

Easy

Conventions

# – requires given linux commands to be executed with root privileges either directly as a root user or by use of sudo command
$ – requires given linux commands to be executed as a regular non-privileged user

Introduction

Users are always the least secure part of a network. Anyone who has any experience as an admin will tell you that most users know absolutely nothing about security. That’s why they’re by far the easiest way for an attacker to gain access to your network.

Wireshark dialog for creating a capture filter

Filtering Packets In Wireshark on Kali Linux

28 September 2018 by Nick Congleton

Introduction

Filtering allows you to focus on the exact sets of data that you are interested in reading. As you have seen, Wireshark collects everything by default. That can get in the way of the specific data that you are looking for. Wireshark provides two powerful filtering tools to make targeting the exact data you need simple and painless.

There are two way that Wireshark can filter packets. It can filter an only collect certain packets, or the packet results can be filtered after they are collected. Of course, these can be used in conjunction with one another, and their respective usefulness is dependent on which and how much data is being collected.

Introduction to Nmap on Kali Linux

28 September 2018 by Nick Congleton

Introduction

Nmap is a powerful tool for discovering information about machines on a network or the Internet. It allows you to probe a machine with packets to detect everything from running services and open ports to the operating system and software versions.

Like other security tools, Nmap should not be misused. Only scan networks and machines that you own or have permission to investigate. Probing other machines could be seen as an attack and be illegal.

That said, Nmap can go a long way in helping to secure your own network. It can also help you to ensure that your servers are properly configured and don’t have any open and unsecured ports. It will also report if your firewall is correctly filtering ports that should not be externally accessible.

Nmap is installed by default on Kali Linux, so you can just open it up and get started.

Test WordPress Logins With Hydra on Kali Linux

25 September 2018 by Nick Congleton

Introduction

There are web forms all over the Internet. Even sites that don’t usually allow regular users to log in probably have an admin area. It’s important when running and deploying a site to make sure that the passwords gating access to sensitive controls and admin panels are as secure as possible.

There are different ways to attack a web application, but this guide is going to cover using Hydra to perform a brute force attack on a log in form. The target platform of choice is WordPress. It is easily the most popular CMS platform in the world, and it is also notorious for being managed poorly.

Remember, this guide is intended to help you protect your WordPress or other website. Use on a site that you don’t own or have written permission to test is illegal.