Hello Linux Geeksters. In this article I will show you how to permanently disable the guest account login on Ubuntu 13.10 Saucy Salamander. For instructions on how to disable the guest login on Ubuntu 13.04 Raring Ringtail, see this article.
The guest account login may create security issues, so it is a good habbit to disable it. And it is not difficult at all. The following instructions work only if you use LightDM as default. For MDM or GDM, this trick does not work.
All you have to do is to append the allow-guest=false line in the /etc/lightdm/lightdm.conf.d/50-unity-greeter.conf file, with root privileges, of course.
sudo sh -c 'echo "allow-guest=false" >> /etc/lightdm/lightdm.conf.d/50-unity-greeter.conf'
As a reminder, Ubuntu 13.10 Saucy Salamander will be released on the 17th of October, 2013. Despite the initial plans, it will not be uses Mir/XMir as default, as a replacement for the good old X.Org server. For more information, read this article.
Reboot and see the modifications.