Category Archives: security

How to add password protection to GRUB2

These instructions are tested with Ubuntu desktop 12.04, but will probably be useful in other Linux distros with GRUB2 as well. The goal is to block everything except booting the default system. In paricular, it should not be possible for … Continue reading

Posted in Linux, security, Ubuntu | 2 Comments

Why can only root listen to ports below 1024?

(This article has been edited since it’s first publication.) In Linux, and other UNIX-like systems, you have to be root (have superuser privileges) in order to listen to TCP or UDP ports below 1024 (the well-known ports). This port 1024 … Continue reading

Posted in Linux, security | 28 Comments