One of my friend forgot his ubuntu password and i tried to fix it by going to recovery mode dropping into root shell and resetting the password for the user
root@username-PC:~# passwd username Enter new UNIX password: Retype new UNIX password: passwd: Authentication token manipulation error passwd: password unchanged
But this time it didn’t work as usual. It showed an error “Authentication token manipulation error”.
I tried googling an found that the file system is not mounted with read/write permission.
From root shell remount file system with read/write permission.
mount -rw -o remount /
Then try changing the password using
Some times it may may throw the same error again, then delete the password for the user from /etc/shadow file using the fllowing command
sudo passwd -d username
Replace username with your’s. Then again change the password using
Happy Hacking 🙂