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1) why can't I invoke sudo if one of my groups is sudo?

2) also I have noticed that /etc/sudoers needs sudo privileges. sudoers.so doesn't exist in /usr/lib but does in /usr/lib/sudo is this correct in 13.04?

user@user-desktop:~$ groups user
user : user adm cdrom sudo dip plugdev lpadmin sambashare
user@user-desktop:~$ sudo
sudo: effective uid is not 0, is sudo installed setuid root?
user@user-desktop:~$ who am i
user pts/0 2013-10-24 08:54 (:0.0)


the response to lsb_release -a;id; sudo whoami was

fred@fred-desktop:~$ lsb_release -a;id; sudo whoami
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 13.04
Release: 13.04
Codename: raring
uid=1000(fred) gid=1000(fred)
sudo: effective uid is not 0, is sudo installed setuid root?

But I have also found my password has been corrupted see below

fred@fred-desktop:~$ passwd fred
Changing password for fred.
(current) UNIX password:
passwd: Authentication token manipulation error
passwd: password unchanged
fred@fred-desktop:~$ su
su: Authentication failure

I know I typed my password correctly and I don't know su password

I booted in recovery mode ran fsck to set permissions to read/write and then root CLI and reset password for fred to what it had been then rebooted but the error messages remain the same!!

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What's the output of this command lsb_release -a;id; sudo whoami Edit your question with the answer. –  Warren Hill Oct 26 '13 at 13:58
Additionally the output of ls -l $(which sudo) might be helpful. –  guntbert Oct 26 '13 at 15:48
There is no su password that account is locked by default. Try changing your password from a recovery console as described here –  Warren Hill Oct 27 '13 at 12:49
If that doesn't fix it take a look at this question: Getting an “Authentication token manipulation” error when trying to change my user password –  Warren Hill Oct 27 '13 at 12:51
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