The kernel is a piece of software that is at the core of an operating system. It usually has complete control over all of the server systems. It is normally the first program loaded after the bootloader has completed its tasks. The kernel then handles the rest of the start-up tasks as well as i/o requests from the system’s software. It then translates those requests into hardware instructions for the CPU (central processing unit).
In this article, we will learn how to switch a Linux firewall from IPtables to nftables on Ubuntu. IPtables, which is based on the Linux kernel Netfilter module, is currently the default firewall for many Linux distributions. It protects against multiple threat vectors and allows your server to block unwanted traffic based on a specific ruleset.
Reading Time: 2minutesIn this article and related video, we will be discussing how to check the kernel version in both Ubuntu and CentOS Linux. The following command works with all Linux distributions, such as Red Hat, CentOS, Debian, and Ubuntu. It also works on other UNIX-like operating systems such as HPUX, FreeBSD, OpenBSD, Solaris, etc. Use the following command to check which kernel version your server is currently running: Continue reading “How To Check the Kernel Version in Linux / Ubuntu / CentOS”→
Reading Time: 6minutesIf you are still using Ubuntu version 16.04, you may want to consider updating to the latest Long Term Support release, version 18.04. In this post, we will cover what a Long Term Support release is and why you would want to use it. You will also learn the significant changes between 16.04 and 18.04. Last, but not least, you will also learn how to upgrade your server from Ubuntu 16.04 to Ubuntu 18.04.
Reading Time: 2minutesOne of the most important things you can do to ensure the security and stability of your Linux server is to keep the kernel updated. Some Kernel updates patch security vulnerabilities and other issues. Kernel patches are released as issues are discovered.
Reading Time: 2minutesThe concept of ‘Kernel hotpatching’, sometimes called live patching, was introduced to the Linux community around 2008. Soon after groups began developing differing implementations of the concept. KernelCare, one of the more popular implementations, was originally released in March 2014 by Cloud Linux, Inc. Continue reading “What Is KernelCare?”→
Reading Time: < 1minuteA vulnerability found in the glibc library, specifically a flaw affecting the gethostbyname() and gethostbyname2() function calls, that allows a remote attacker to potentially execute arbitrary code. CentOS 5, CentOS 6, and CentOS 7 are potentially affected, thus we want to highlight the following information.
Liquid Web package repositories have been updated. Many servers (barring those with updates disabled) have received an update that patches this vulnerability, however, a reboot will still be required in those cases.
Reading Time: < 1minuteA vulnerability found in the Linux kernel, specifically a flaw in fault handling associated with the Stack Segment (SS), allows an unprivileged user to potentially gain privileges. CentOS 4, CentOS 5, CentOS 6, and CentOS 7 are potentially affected, thus we want to highlight the following information. Continue reading “CVE-2014-9322 Vulnerability Info for Red Hat and CentOS”→
It is highly recommended that you take an image of your existing server prior to following these instructions. Doing so will ensure that if something unexpected occurs, you will be able to restore your server from the backup image.