Raspberry Pi devices are commonly used to host a variety of lightweight services as they can do so very affordably. A simple example would be a web server, which handles user requests whenever someone navigates to a website. In order to make sure these services are accessible either on the local network or over the internet, we must make sure that the corresponding ports are open. Checking for open ports is also an essential security task that all administrators should perform in order to make sure that their Raspberry Pi only has the ports open that are necessary.
firewalld is the default firewall on Red Hat Enterprise Linux, and it’s enabled by default, but it’s possible to disable the firewall on Redhat, and you’ll also see how to check firewall status in Linux. Normally, there should not be a need to disable the firewall, but it may be quite handy for testing purposes or other scenarios. In this tutorial, you’ll see how to check the status of firewalld, enable or disable the service from starting automatically upon system boot, and how to stop or start the firewalld service in RHEL.
The objective of this guide is to show how to enable and disable the WiFi on Kali Linux. This can be done either by GUI or command line, and we’ll be showing the step by step instructions for both methods in this tutorial. This will be helpful if you’re having trouble connecting to a wireless router, or you plan to do some WiFi scanning and cracking with Aircrack-ng, for example.
It’s possible to reset Kali Linux password in the event that you are no longer able to login to the root user account. This happens if you haven’t logged in for a while and have since forgot Kali Linux password. In case you have not already tried, the default Kali password for root user is
toor (root backwards) on VMWare and live images. Try logging in with this password before resetting the Kali Linux password.
In order to enable root login for Kali Linux, we must set the the root password manually. In past versions of Kali Linux, users were able to log in directly to the root account by default. On more recent versions, this has been disabled. The reasoning behind this change should be obvious, but if you’re a Kali user, you probably know your way around a Linux system by now, and there’s not much risk in letting you use the root account to log in.
The firewall on a Raspberry Pi will, by default, block incoming connections to certain ports. This is a security feature, but may cause problems if you try to configure an SSH server on your Raspberry Pi, host a website, or otherwise host some service that needs to accept incoming connections. The usual answer to this problem is to configure the firewall to accept the connections on the particular ports that you need to open. Another alternative is to disable the firewall completely.
Being aware of your current Raspberry Pi OS version will help you know when it is time to update. It is important to know the version of your Raspberry Pi system, as new versions are released based on Debian’s release schedule, and new updates are issued all the time. Staying up to date will keep your Raspberry Pi secure and ensure that you have the newest software available. All Raspberry Pi models can run the same operating system, so updates are universal across all devices.
Hex editors allow users to edit a binary file after it has already been compiled. Ordinarily, you should make changes to a program by editing the source code and compiling it into an executable file. But if you do not have access to the source code, it is still possible to change various bytes of data of the compiled file, in the hopes that your edit will yield the desired results. This is a hacky solution that can be used for both honest and nefarious purposes.
If you have one or more files that you need to send to a friend or store for a long time, compressing the files into a .zip archive is a good way to save on space and combine all files into a single object. If you need to keep the file contents private, for fear that they could be intercepted by the wrong party, or that someone could try to access them on your own system, then it is possible to add a password to your zip file. In this tutorial, you will learn how to zip files and add a password to your zip archive on a Linux system.
Processes that utilize the network connection of your Linux system will occupy a port whenever they are uploading or downloading data, or listening for incoming connections. A common example present on many Linux servers would be the SSH protocol, which listens for and accepts incoming connections on port 22 by default. Ordinarily, administrators can kill a process using the PID number, or by specifying the process name. But in some cases, we may want to kill a process according to which port number it is using.
It may be necessary to configure Linux IP forwarding on a Linux system in certain scenarios. If the Linux server is acting as a firewall, router, or NAT device, it will need to be capable of forwarding packets that are meant for other destinations (other than itself). Linux uses the net.ipv4.ip_forward kernel variable to toggle this setting on or off.
Everyone, nowadays, has several accounts and credentials to take care of, that’s why everyone needs a decent and possibly open source password manager. When it comes to managing passwords there are many choices available on Linux: in the past, for example we talked about “pass”, a great, command line oriented, password-manager based on standard tools such as GPG and git. In this article we explore an alternative which can be the ideal solution for individuals and small organizations: Vaultwarden.