Tag Archives: CentOS

Scanvus – my open source Vulnerability Scanner for Linux hosts and Docker images

Hello everyone! This video was recorded for the VMconf 22 Vulnerability Management conference, vmconf.pw. I will be talking about my open source project Scanvus. This project is already a year old and I use it almost every day.

Alternative video link (for Russia): https://vk.com/video-149273431_456239100

Scanvus (Simple Credentialed Authenticated Network VUlnerability Scanner) is a vulnerability scanner for Linux. Currently for Ubuntu, Debian, CentOS, RedHat, Oracle Linux and Alpine distributions. But in general for any Linux distribution supported by the Vulners Linux API. The purpose of this utility is to get a list of packages and Linux distribution version from some source, make a request to an external vulnerabililty detection API (only Vulners Linux API is currently supported), and show the vulnerability report.

Scanvus can show vulnerabilities for

  • localhost
  • remote host via SSH
  • docker image
  • inventory file of a certain format

This utility greatly simplifies Linux infrastructure auditing. And besides, this is a project in which I can try to implement my ideas on vulnerability detection.

Example of output

For all targets the output is the same. It contains information about the target and the type of check. Then information about the OS version and the number of Linux packages. And finally, the actual information about vulnerabilities: how many vulnerabilities were found and the criticality levels of these vulnerabilities. The table shows the criticality level, bulletin ID, CVE list for the bulletin, and a comparison of the invulnerable fixed package version with the actual installed version.

This report is not the only way to present results. You can optionally export the results to JSON (OS inventory data, raw vulnerability data from Vulners Linux API or processed vulnerability data).

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End of CentOS Linux. Where to migrate?

Hello everyone! As you probably know, CentOS Linux, the main Enterprise-level Linux server distribution, will soon disappear. It wasn’t hard to predict when RedHat acquired CentOS in 2014, and now it is actually happening. End of life of CentOS Linux 8 was 31.12.2021. There won’t be CentOS Linux as downstream for RedHat anymore. Only CentOS Stream, that will be upstream for RedHat, more or less a testing distro like Fedora.

Of course, it is a matter of debate whether security guys can actually decide which Linux distributions a company will use and set that as a requirement. But in any case, the security guys will definitely take part in the decision. I made a poll in my Telegram channel. 113 people voted. So, let’s take a look at the results and discuss which of the Linux distributions we can recommend to IT teams.

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CentOS 8 with IceWM Desktop Environment

Do you need CentOS 8 with IceWM as desktop Operating System? Most likely not. Especially if you want it to work smoothly without any worries and troubles. However, if you enjoy playing with new desktop environments, you might find it fun.

CentOS 8 with IceWM desktop environment

My reasons were as follows:

  1. I wanted to use the same Linux distribution for server and desktop. Just to minimize possible surprises during the deployment.
  2. I wanted to know what is going on in the RPM-based part of Linux world. The only way to achieve this is to use such distribution every day.
  3. I was tired of problems with the Virtual Box guest additions in CentOS 7 (yes , I run it all as a virtual machine), especially after the 3.10 kernel updates. It was time to move on.
  4. I didn’t want to use Gnome 3, because it’s slow and ugly (however it’s fully functional!). And there were no other DEs in CentOS 8 repositories at that time.

So, I tried CentOS 8 with IceWM (installed it from source) and it worked. IceWM is small, very fast, ascetic, and in some ways quite intuitive. There were some problems with the clipboard (in xTerm and with VBox shared clipboard) and with language switching, but I figured it out and I think that I would probably continue to use it. Below are some notes on how I installed it and resolved the issues.

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Dante SOCKS5 server with authentication

It’s not so obvious that socks servers with authentication are a necessary thing.

  1. You can run a “local socks service” simply by connecting to a remote host via ssh (with -D <port>)
  2. Most of software products, that support socks, don’t support socks servers with authentication

The last fact I find very unfortunate, because using socks without having to monitor ssh connection is much more comfortable. But if the software actually supports socks with authentication you can try Dante server.

Dante SOCKS5 server with authentication

Here’s how to install and configure it in CentOS 7.

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First steps with Docker: installation in CentOS 7, vulnerability assessment, interactive mode and saving changes

Docker and containerization are literally everywhere. IMHO, this changes the IT landscape much more than virtualization and clouds. Let’s say you have a host, you checked it and find out that there are no vulnerable packages. But what’s the point if this host runs Docker containers with their own packages that may be vulnerable? Add to this the issues with complex orchestration systems, such as Kubernetes, completely different DevOps subculture with their own terms, slang, beliefs, priorities, and the situation begins to look like complete IT Hell. 🙂

First steps with Docker

But it seems that Docker will be here for a long time, so we will have to live with it. 😉 Here I will not write what Docker is and how it works. There are many publications about this. I personally interested in what actually we can do with these weird “virtual machines”, how can we run and assess them.

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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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Assessing Linux Security Configurations with SCAP Workbench

Recently I had a chance to work with OpenSCAP. It’s a set of free and open-source tools for Linux Configuration Assessment and  a collection security content in SCAP (Security Content Automation Protocol) format.

In this post I will write about SCAP Workbench. It is a GUI application that can check the configuration of your local Linux host (or the remote host via ssh; note that agent installation is required), and show the settings that are not comply with some security standard, for example PCI DSS or DISA STIG.

SCAP Workbench PCI DSS CentOS7 localhost

Moreover, you can generate the script for automated remediation. You can also create your own scan profiles based on existing  SCAP content.

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