CentOS

CentOS Linux Howtos and Tutorials

How To Patch and Protect Linux Kernel Stack Clash Vulnerability CVE-2017-1000364 [ 19/June/2017 ]

Posted on in Categories , , , , , last updated June 20, 2017

A very serious security problem has been found in the Linux kernel called “The Stack Clash.” It can be exploited by attackers to corrupt memory and execute arbitrary code. An attacker could leverage this with another vulnerability to execute arbitrary code and gain administrative/root account privileges. How do I fix this problem on Linux?

How to prevent sed -i command overwriting my symlinks on Linux or Unix

Posted on in Categories , , , , , , , , , last updated June 13, 2017

I recently ran a command ‘sed -i 's/CONFIG_1/CONFIG_OPT_2/g' /etc/nginx/sites-enabled/*.conf‘ on a Debian Linux server. However, the sed command destroyed the link and created a regular file in place of the link file. How can I prevent my ‘sed -i’ command from destroying symlinks on Linux or Unix-like system?

How to allow root login from one IP address with ssh public keys only

Posted on in Categories , , , , , , , last updated June 10, 2017

I am using MacOS on the desktop and Ubuntu Linux on the server. I disabled root login over ssh and enabled ssh based public key login. However, I recently added second Ubuntu server. I need to sync file between two using rsync command. Is there any way that I can log from the second server into my first server with root user from second server IP address only ([email protected] }# ssh [email protected]) without reducing OpenSSH server security option?