Tag Archives: Ubuntu

Packabit project: building Nmap deb packages for Ubuntu

During the long New Year holidays (30 dec – 8 jan) I started a new project: Vagrant-based Linux package builder called Packabit. I thought it might be nice to have scripts that will automatically build a Linux packages from sources and will NOT litter main system with unnecessary packages. Something like a very simplified build server.

Packabit - Vagrant-based Linux package builder

Why might someone want to build Linux packages on their own?

Official repositories of Linux distros usually contain pretty old versions of packages. Let’s take, for example, Nmap. The only version of Nmap available in the repository for Ubuntu 18.04.1 LTS is 7.60 , and the latest stable version of Nmap available on official website is 7.70.

Release dates according Nmap changelog:

  • Nmap 7.70 [2018-03-20]
  • Nmap 7.60 [2017-07-31]

The latency is more than a year.

Is it really necessary to use the latest version? Actually, yes. Every new version of Nmap contain more banner detects and service detects and produce more adequate results. Nmap project offers official packages only for RPM-based distributions: CentOS, RHEL, Fedora, etc. And if you need packages for DEB-based distributions, Debian, Ubuntu, Kali, etc. you should build them yourself.

What is the Packabit?

Currently it’s just 2 bash scripts for building stable Nmap package for Ubuntu 18.04: one is for creation and launching Vagrant virtual machine, the other runs on guest virtual machine and build Nmap package from the sources.

How to try it

I want this project to be as opensource as possible. If anyone wants to give it a try, get it from Github. For the end-user it looks like this: run the script build_nmap.sh, wait for 10 minutes and get new package from the packages directory. There won’t be any litter in a process. Each time a new virtual machine for building will be automatically created and then destroyed.

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Making Vulnerable Web-Applications: XXS, RCE, SQL Injection and Stored XSS ( + Buffer Overflow)

In this post I will write some simple vulnerable web applications in python3 and will show how to attack them. This is all for educational purposes and for complete beginners. So please don’t be too hard on me. 😉

Vulnerability Examples

As a first step I will create a basic web-application using twisted python web server (you can learn more about it in “Making simple Nmap SPA web GUI with Apache, AngularJS and Python Twisted“).

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Deploying VirtualBox virtual machines with Vagrant

I often use virtual machines for various tasks: from building software packages to testing software products or PoCs for vulnerabilities. Creating a virtual machine in Oracle VirtualBox is a time-consuming and annoying process: set parameters of VM, attach iso, make dozens of clicks in OS installation GUI interface, wait until everything is installed, configure network and install guest additions.

Vagrant and Oracle VirtualBox

Of course you can create an image of the base machine once and clone it each time you need it. But from time to time you will still need to recreate this image, for example for a new Linux release. It would be much easier, if we could get a fresh and clean Virtual Machine that meets our requirements and with minimal effort. And this is what Vagrant by HashiCorp does.

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Vulnerability Databases: Classification and Registry

What publicly available Vulnerability Databases do we have? Well, I can only say that there are a lot of them and they are pretty different. Here I make an attempt to classify them.

It’s quite an ungrateful task. No matter how hard you try, the final result will be rather inaccurate and incomplete. I am sure someone will be complaining. But this is how I see it. 😉 If you want to add or change something feel free to make a comment bellow or email me@avleonov.com.

The main classifier, which I came up with:

  • There are individual vulnerability databases in which one identifier means one vulnerability. They try to cover all existing vulnerabilities.
  • And others are security bulletins. They cover vulnerabilities in a particular product or products. And they usually based on on patches. One patch may cover multiple vulnerabilities.

I made this diagram with some Vulnerability Databases. Note that I wanted to stay focused, so there are no exploit DBs, CERTs, lists of vulnerabilities detected by some researchers (CISCO Talos, PT Research, etc.), Media and Bug Bounty sites.

Vulnerability Databases classification

For these databases the descriptions of vulnerabilities are publicly available on the site (in html interface or downloadable data feed), or exist in a form of paid Vulnerability Intelligence service (for example, Flexera).

On one side there are databases of individual vulnerabilities, the most important is National Vulnerability Database. There are also Chinese, Japanese bases that can be derived from NVD or not.

On the other side we have security bulletins, for example RedHat Security Advisories.

And in the middle we have a Vulnerability Databases, for which it is not critical whether they have duplicated vulnerability IDs or not.

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Vulchain scan workflow and search queries

This post will be about my Vulnerability Scanner project – Vulchain. Recently I’ve spent couple of my weekends almost exclusively on coding: refactoring the scan engine, creating API and GUI.

Vulchain scan workflow and search queries

I was doing it because of the conferences, where I will be speaking soon:

Pretty intense schedule for a guy who spends most of his time in PyCharm and Linux console. 😉 Very excited! So, it seemed right to add a couple of slides about my project and show that something is already working.

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New Vulners.com services for Linux Security Audit and Vulnerability Alerting

A few weeks ago I was describing how to perform Linux Vulnerability Assessment without a Vulnerability Scanner. I also wrote in “Vulnerability scanners: a view from the vendor and end user side” that vulnerability scanning is not rocket science and it is easy to make your own scanner for vulnerabilities for a particular OS. Especially it is a popular Linux Distribution.

But. It’s one thing to write that you can do it, and another thing to develop a script for home use, and quite another thing to make a publicly available and efficient service…

Vulners Team guys have actually created such free Linux Vulnerability Audit service!

Linux Vulnerability Audit Service

First of all, they made a GUI where you can specify OS version (usually it is in the /etc/os-release file), list of packages installed on the host and get the list of vulnerabilities.

For example, here are the vulnerabilities for my Ubuntu Laptop, which I update frequently:

Ubuntu Vulners Linux Audit Input

One vulnerability was found:

Ubuntu Vulners Linux Audit Results

But GUI is good for demonstration. In real life, you can use Vulners Audit API. It will return list of vulnerabilities in JSON.

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Vulnerability Assessment without Vulnerability Scanner

This will be a practical confirmation of my thesis from “Vulnerability scanners: a view from the vendor and end user side“: the scanner for one operating system is easy to make. I also want to demonstrate that data collection and data analysis for Vulnerability Assessment may be successfully performed separately. There is no need to take the data directly from the vulnerable hosts, when it is already stored somewhere else, for example in IT monitoring systems.

Assessment without vulnerability scanner

The opacity of data collection and the need to have a privileged account on the remote host, traditionally causes conflicts between IS and IT departments and complicates implementation of VM process.

So, to detect vulnerabilities on our Linux host we need to know what version of the packages contain vulnerabilities, which versions of packages are installed on our hosts, and learn how to compare versions.

How do I know which versions of packages are vulnerable?

Vulnerable versions of packages are listed in official security bulletins:
RHEL – https://access.redhat.com/errata/RHSA-2016:0304
CentOS – https://lists.centos.org/pipermail/centos-announce/2015-April/021064.html
Debian – http://www.debian.org/security/2015/dsa-3197
Ubuntu – http://www.ubuntu.com/usn/usn-2537-1/

CESA bulletin example

Of course, you will need to parse them first. Or you can just download the same content already parsed and presented in JSON format with Vulners.
download CESA bulletins from Vulners
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