I am running a Ubuntu 12 machine, and have recently been working to secure it. I made all the changes from this guide. I am not running a Linode, but I used these as a starting point for setting up the firewall and such.
All went smoothly, and I have been using the machine for some time now. I tried to lock some users' accounts, with the passwd -l
command, and that was successful. However, when I try to add a new user, or change my password, I have the strangest error:
myuser@mymachine:~$ passwd
Old Password:
passwd: Authentication token manipulation error
passwd: password unchanged
Or, when adding a new user:
myuser@mymachine:~$ sudo adduser mynewuser
Adding user `mynewuser' ...
Adding new group `mynewuser' (1011) ...
Adding new user `mynewuser' (1002) with group `mynewuser' ...
Creating home directory `/home/mynewuser' ...
Copying files from `/etc/skel' ...
passwd: Authentication token manipulation error
passwd: password unchanged
Try again? [y/N]
I searched for this error, and the vast majority of problems were solved by remounting / as read and write. However, this is not the problem, as it is mounted as read and write (I confirmed). Note that the same error is encountered from different users, and from root trying to change other users' passwords.
Do you have any insight as to why I am (seemingly spontaneously) getting this error? I have not done any manual editing of the shadow
or passwd
files--or really made any change to user authentication at all.
In case it is relevant:
ls -lh /etc/passwd -rw-r--r-- 1 root root 3.2K Jul 23 17:26 /etc/passwd
ls -lh /etc/shadow -rw------- 1 root shadow 3.1K Jul 23 17:20 /etc/shadow