"no valid sudoers sources found, quitting" error while chmodding /var/www

I'm new to Ubuntu and just installed LAMP. I'm trying to paste files into the /var/www/ directory so i can test my PHP projects, but I can't.

I have searched on the web and all I read is: "type sudo chmod 077 /var/www/" or something like that, but my machine throws back this:

sudo: /etc/sudoers is mode 0777, should be 0440
sudo: no valid sudoers sources found, quitting

What am I doing wrong?

2 Answers

Your problem seems to be a bigger one. Try the following:

• Restart your computer

• Boot into Recovery Mode (select the "Recovery" option from the boot screen. If you're single-booting Ubuntu, you need to hold the Shift key to get to the GRUB menu)

• At the prompt you see, select "Drop to root shell prompt"

• At the command prompt (which should say root@your-computer:~#, enter:

   chmod 0440 /etc/sudoers

• Then, restart your machine

   shutdown -r now

Now, you should be able to use sudo again. It seems you've tried a few wrong commands before.

Note:

Always take care that you know what you're doing when you use sudo.

Another note:

Running sudo chmod 077 /var/www/ is definitely not what you want to do. If you want to set permissions on /var/www, it would be advisable to create a new group of users that have write-access to the directory.

sudo addgroup www-users
sudo adduser <your-username> www-users

Replace <your-username> with your real username. This will add a new group www-users and add yourself to it.

Then, add the webserver user to it:

sudo adduser www-data www-users

And give the right permissions:

sudo chgrp www-users /var/www
sudo chmod –R 775 /var/www
sudo chmod g+s /var/www

If you have the root password, type in su -c chmod 0440 /etc/sudoers. This should fix your issue.

The issue is most likely caused by the fact that something changed the permission value of your /etc/sudoers file to 0777, which makes it write-able by everyone, which is a major security risk. Therefore sudo denies you access, since anybody could have gained sudo access.