Modifying an invalid sudoers file

For those who come across the missing sudoers file which looks something like this:

/etc/sudoers is owned by uid 777, should be 0

Follow the below steps to get rid of this problem:

You have to reboot into recovery mode and first do the folllowing:

1)Choose the 'Enable networking' option.

2)Choose the 'Drop to root shell' option.

and then run visudo as follows:

pxexec visudo

then change last line of sudoers.so from: include /etc/sudoers

to: include /etc/sudoers.d

and finally

reboot with normal grub option.

This should solve your problem.