Despite some severe bugs in sudo, it remains the defacto tool to gain root shell or run command as another user on Linux, macOS, and Unix-like systems. The sudo command allows the system administrator to grant an individual user access to unprivileged commands. For instance, I can give developers the ability to restart the Apache webserver or PHP/Python process on a Linux server. Let us see how to remind developers and unprivileged users about the power of sudo for fun and profit. In this quick tip, I will show you how to add some spice to your sudo session with a lecture file on Linux or Unix.
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Raspberry Pi is a little useful computer for learning programming and building projects. It comes with Debian Linux based modified operating system called Raspbian. It is the most widely installed OS on RPi. In a recent update, the Raspberry Pi OS installed a Microsoft apt repository on all machines running Raspberry Pi OS without the person’s or admin’s knowledge. Every time a Raspbian device is updated by having this repo, it will ping a Microsoft server. Microsoft telemetry has a bad reputation in the Linux community. Let us see why and how this matters to Linux users.
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Linode is an original cloud platform and founded before AWS. Back then, we used to call them VPS (Virtual Private Server). Recently they added a new firewall feature to control network access to my Linode server from the Cloud. Let us test drive Linode cloud firewall.
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Bonsai (盆栽) is nothing but planting in a try. It is old age Japanese art of growing small trees in pots. Now you can do that with your Linux or Unix terminal easily for fun and profit. Let us look into the Bonsai tree generator called cbonsai created in Clang and Bash.
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Any logged-in unprivileged user can abuse an old bug in sudo to gain root privileges. It was rated as an important security issue for Linux and Unix-like operating systems. The Qualys research team has discovered the heap overflow vulnerability in sudo itself has been hiding in plain sight for nearly 10 years. The bug allows any local users to gain root access without authentication (no user’s password needed). We need to apply patches to our operating systems as soon as possible.
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Last year, the Raspberry Foundation also released a brand new version of the Raspberry PI PC (personal computer), and it is directly built into a small-sized keyboard. Now there is more good news for hackers and hardware developers. They just announced their first microcontroller-based product named Raspberry Pi Pico. This small device is priced at only US $4. Unbelievable price. Let us find out about Raspberry Pi Pico hardware specs and software support.
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As you know, Red Hat recently announced that CentOS Linux 8, as a rebuild of RHEL 8, will end in 2021. CentOS Stream continues after that date, serving as the upstream (development) branch of Red Hat Enterprise Linux. The news met with a strong reaction from the open-source community and CentOS users. Today, Red Hat released a new option where RHEL developer subscriptions can now be used in production environments. The developers and team can have up to 16 systems. In other words, it is a no-cost RHEL that small groups and developers can use to build packages and in production environments.
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We use the df command to show how much disk space is free on mounted file systems in Linux, macOS, and Unix-like systems. We also have the du command to estimate file space usage. We now have another fancy and fantastic looking tool called duf to display statistics on free disk space in Unix, Linux, macOS, *BSD, Android, and Windows written in Golang.
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On Linux, we encrypt our partitions and entire disk using Linux Unified Key Setup-on-disk-format (LUKS) for security and privacy reasons. We unlock LUKS protected disk by providing a passphrase at boot time. You need to be in front of your computer or use a remote console to open the encrypted disk under Linux at boot time. However, if your system is in the basement, remote datacenter/office, or upstairs office, you won’t able to unlock and boot your Linux box. We can use the Dropbear SSH server for LUKS encrypted Debian or Ubuntu or any other Linux distro via SSH to solve this problem. Let us see how to unlock LUKS using Dropbear SSH keys in Linux at boot time.
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