sudoers error & ubuntu server recovery mode

**doctorproctor** · October 8th, 2011

Greetings -- I (and all other admin group members) can no longer run sudo on Ubuntu Server 10.04 LTS as we receive the following group ID error:

"/etc/sudoers is owned by gid 113, should be 0"

How can we replace the file sudoers with one with correct permissions? A quick search suggests that recovery mode is the only way, though I'd need to convey appropriate instructions to my IT people as I don't have physical access to the (virtual) server and have no idea how it's done in Ubuntu Server.

Many thanks,

Jim

**bbqroast** · October 8th, 2011

Only possible with physical access, UNLESS you can find someone who is a member of group 113 and do it from their account (they should have SUDO access).

**matt_symes** · October 8th, 2011

Hi

Originally Posted by doctorproctor

Greetings -- I (and all other admin group members) can no longer run sudo on Ubuntu Server 10.04 LTS as we receive the following group ID error:

"/etc/sudoers is owned by gid 113, should be 0"

How can we replace the file sudoers with one with correct permissions? A quick search suggests that recovery mode is the only way, though I'd need to convey appropriate instructions to my IT people as I don't have physical access to the (virtual) server and have no idea how it's done in Ubuntu Server.

Many thanks,

Jim

Did somebody chown the sudoers files ? Did they change the ownership of any other system files ?

I would be concerned what other system files may have changed.

You may need to boot into a LiveCD/USB to change it back after mounting it .

Code:

chown 0:0 <mount_point>/etc/sudoers

Make sure the permissions are 440

Code:

chmod 440 <mount_point>/etc/sudoers

As i said before though, have the permissions of any other system file changed ?
You need to find out how this happened.

Out of interest which group is 113 ?

Code:

grep 113 /etc/group

Kind regards

**doctorproctor** · October 8th, 2011

Thanks for your replies so far. Group id 113, I believe, is admin: I and one other user are in 113, there are no other users, and neither of us can use sudo at present; apparently, /etc/sudoers requires owner and group to be root and root (0:0) in order for sudo to work (!).

This mistake was made via an errant recursive chgrp applied to /etc/; not sure how critical this is for other files in /etc/ in addition to sudoers (presumably it stopped after sudoers file changed?). We see no other problems to the system, nothing in the error logs, etc. so far.

I studied info on LiveCD booting, but this seems to apply to desktop vs. server Ubuntu: will this work for server? (I believe our IT people are running virtual servers.)

Thanks again,

Jim

**CharlesA** · October 8th, 2011

Depending on who you chgrp'd them to, it could cause problems down the road.

Anyhow - boot into recovery mode (hold down shift at the grub screen and select recovery mode) and chown it back to root:

Code:

chown root:root /etc/sudoers

**doctorproctor** · October 8th, 2011

Thanks again. So, is there an Ubuntu utility to check/fix file permissions (including owner/group)? Alternatively, would these permissions be updated during upgrade to 11.04?

Regards,

Jim