www.cyberciti.biz Open in urlscan Pro
2606:4700:10::6816:3ea6  Public Scan

Form analysis
2 forms found in the DOM

GET https://www.google.com/cse

<form method="GET" class="search-form" action="https://www.google.com/cse" target="_top">
  <div class="search-form-inner">
    <input name="cx" type="hidden" value="c8e444503670f107a">
    <input name="ie" type="hidden" value="UTF-8">
    <input class="nixcraftsearchbox" type="search" placeholder="🔎 To search, type &amp; hit enter..." name="q" required="">
  </div>
</form>

GET https://www.google.com/cse

<form method="GET" class="search-form" action="https://www.google.com/cse" target="_top">
  <div class="search-form-inner"> <input name="cx" type="hidden" value="c8e444503670f107a"> <input name="ie" type="hidden" value="UTF-8"> <input class="nixcraftsearchbox" type="search" placeholder="🔎 To search, type &amp; hit enter..." name="q"
      required=""> </div>
</form>

Text Content

nixCraft
Please support nixCraft by subscribing to Patreon and keep this site Ads free.




HOW TO BLOCK AI CRAWLER BOTS USING ROBOTS.TXT FILE




Are you a content creator or a blog author who generates unique, high-quality
content for a living? Have you noticed that generative AI platforms like OpenAI
or CCBot use your content to train their algorithms without your consent? Don’t
worry! You can block these AI crawlers from accessing your website or blog by
using the robots.txt file.
[continue reading…]


DEBIAN LINUX 12.1 RELEASED WITH SECURITY UPDATES




Debian Linux project announces the first update of the Debian project’s stable
distribution, Debian 12 (codename “bookworm”) named Debian 12.1. This update
mainly addresses security issues and significant problems. Security advisories
have been published and are now available to download.
[continue reading…]


SETTING UP VSCODE FOR ANSIBLE LIGHTSPEED AI IN UBUNTU 22.04 DESKTOP



Click to enlarge

Red Hat launched the Ansible Lightspeed Code Assistant Generative AI with IBM
Watson Code Assistant in May 2023. This preview is now available to all Ansible
users, allowing them to explore the technology, provide feedback to Red Hat, and
further train the AI model. In this brief blog post, I will share my personal
experience with installing and utilizing Ansible Lightspeed AI to create
playbooks in VSCode using Ubuntu Linux 20.04 LTS desktop.
[continue reading…]


HOW TO UPGRADE FREEBSD 13.1 TO 13.2 RELEASE



Click to enlarge

The FreeBSD Release Engineering Team is announcing the availability of FreeBSD
version 13.2-RELEASE on 11/April/2023. It is the third release of the stable/13
branches. I updated my FreeBSD version 13.1 to 13.2 using the CLI over an
ssh-based session. Here are my quick notes.
[continue reading…]


NVTOP – AWESOME LINUX TASK MONITOR FOR NVIDIA, AMD & INTEL GPUS






The nvtop command is an excellent task monitor for Linux users for NVIDIA, AMD
and Intel GPUs (Graphics Processing Units). It is just like your top command or
htop command and efficiently handles multiple GPUs in your system and shows
details about them in a htop format. Let us see how to install the nvtop command
on your Linux distro and monitor GPU tasks.
[continue reading…]




HOW TO SKIP CHATGPT FROM WIREGUARD OR OPENVPN ON LINUX


nixCraft Patreon supporters can download the PDF version here.

ChatGPT (short for Chat Generative Pre-trained Transformer) is a chatbot by
OpenAI. It provides answers to your queries using learning techniques based on
AI/ML. Unfortunately, ChatGPT deny access when connected via VPN (Virtual
Private Network) such as WireGuard or OpenVPN, and you will be blocked with the
following message:

Let us see how to skip the ChatGPT domain from WireGuard or OpenVPN access while
you can access corporate resources behind VPN.
[continue reading…]


HOW TO SET UP SSH KEYS WITH YUBIKEY AS TWO-FACTOR AUTHENTICATION (U2F/FIDO2)


Patreon users download the PDF version.

All Linux and Unix servers are managed manually or by automation tools such as
Ansible using ssh. For example, say you have a server at Linode or AWS. Then you
copy your public ssh key to a remote cloud server. Once copied, you can now
login to those servers without a password as long as ssh keys are matched. It is
the best practice. Unfortunately, you are not protecting ssh keys stored on a
local desktop or dev machine at $HOME/.ssh/ directory. If your keys are stolen,
an attacker can get access to all of your cloud servers, including backup
servers. To avoid this mess, we can protect our ssh keys stored on local
dev/desktop machines using physical security keys such as YubiKey.

In both cases, you need to insert your YubiKey (or any FIDO2 compatible hardware
key) into a USB port and complete the authentication. In other words, ssh login
will not work when malware or attacker has stolen your passphrase and ssh keys
as they can not insert YubiKey and press the button on it to complete OTP for
ssh keys.

In the corporate environment, we have a bastion host that allows ssh access with
Yubikey. It is a special-purpose server on a network specifically designed and
configured to withstand attacks. The server generally hosts an sshd process, and
all other services are removed. Once logged into bastion host, you can access
all other cloud servers easily.
[continue reading…]


DNS SETTINGS TO AVOID EMAIL SPOOFING AND PHISHING FOR UNUSED DOMAIN




As you may know, email spoofing allows attackers to pose as someone else to gain
illegal profit. For example, I only use webmaster@cyberciti.biz for
communication, but someone might create a spoofed-up email, say
info@opensourceflare.com, to trick someone. This is called email spoofing with
fake headers as follow:
Date: Thu, 24 Oct 2021 12:46:10
From: nixCraft <info@opensourceflare.com>
Reply-To: info@opensourceflare-email.com
To: <my@personal_gmail_com>
Correct headers are often not checked by receiving email servers, and
my@personal_gmail_com may think the email is from me. Here is the thing I don’t
use opensourceflare.com for email communication at all. So how do I prevent
illegitimate email traffic on my domain? In this tutorial, I will explain how to
configure DNS settings that tell receiving email servers this domain is not
configured for emailing purposes and the attacker maliciously sending email on
my behalf.
[continue reading…]


HOW TO PROTECT LINUX AGAINST ROGUE USB DEVICES USING USBGUARD



usbgurd

You deployed a perfect firewall and other network security policies preventing
unauthorized access to the user’s desktop computer over a network. However, you
still need to block USB device access. We can configure a Linux desktop security
policy to protect your computer against rogue USB devices (a.k.a. BadUSB) by
implementing essential allow and blocklisting capabilities based on device
attributes. For instance, I can define what kind of USB devices are authorized
and how a USB device interacts with the Linux system. For example, I can define
policy allowing Yubikey with serial number “XYZ” and USB LTE modem with serial #
“ABC.” Every other USB device access is denied by default.
[continue reading…]




A CAUTIONARY TALE ABOUT LOCKING LINUX & FREEBSD USER ACCOUNTS




Like every other solo developer and sysadmin, I do stuff using ssh. Some stuff
is automated using scripts, and others require ssh login. For example, one of my
scripts logs into my Linux and FreeBSD server using public ssh keys and does a
particular type of work for me. I have a dedicated user account for that purpose
called autovivek on Raspberry PI 4 for Ansible and custom script automation.
Here is how it works:
{rpi4:~}$ ssh autovivek@192.168.2.17 /path/to/taks1
In other cases, it sends scripts and then executes them on the remote server
named 192.168.2.17. Sounds good, right? So, when I need to make backups and
other tasks, I lock down the autovivek user account on the server so that it
will not modify data on disks. For example, here is how to lock down a user
account:
{linux-server:~}$ sudo usermod -L -e 1 autovivek
## OR ##
{freebsd-server:~}$ sudo pw lock -n autovivek


A CAUTIONARY TALE ABOUT LOCKING LINUX AND FREEBSD USER ACCOUNTS

However, I soon discovered that a user named autovivek can still log into the
server and make changes despite being locked down on both Linux and FreeBSD
servers. I foolishly assumed that it would work out of the box. But, boy, I was
in for a big surprise. [continue reading…]

Older Posts
     


🤓 NIXCRAFT SHOP 👇


🔎 SEARCH





🔥 FEATURED ARTICLES

 * 1
   30 Cool Open Source Software I Discovered in 2013
 * 2
   30 Handy Bash Shell Aliases For Linux / Unix / Mac OS X
 * 3
   Top 32 Nmap Command Examples For Linux Sys/Network Admins
 * 4
   25 PHP Security Best Practices For Linux Sys Admins
 * 5
   30 Linux System Monitoring Tools Every SysAdmin Should Know
 * 6
   40 Linux Server Hardening Security Tips
 * 7
   Linux: 25 Iptables Netfilter Firewall Examples For New SysAdmins
 * 8
   Top 20 OpenSSH Server Best Security Practices
 * 9
   Top 25 Nginx Web Server Best Security Practices
 * 10
   My 10 UNIX Command Line Mistakes




📧 SIGN UP FOR MY NEWSLETTER




👀 /ETC

 * ➔
   Howtos & Tutorials
 * ➔
   Linux shell scripting tutorial
 * ➔
   RSS/Feed
 * ➔
   About nixCraft
 * ➔
   nixCraft Shop
 * ➔
   Mastodon

     

©2002-2024 nixCraft • Privacy • ToS • Contact/Email • Corporate patron Linode &
Cloudflare

     