I had to change a webmin username’s password recently. After spending few minutes Googling I came to the answer here is a quote from Webmin Website
How do I change my Webmin password if I can't login?
Included with the Webmin distribution is a program called changepass.pl to solve erecisely this problem. Assuming you have installed Webmin in
/usr/libexec/webmin, you could change the password of the admin user to foo by running
/usr/libexec/webmin/changepass.pl /etc/webmin admin foo
This works like a charm and I was able to change a certain username’s password on a CentOS 5.3 right out of the box.
Probably on other Linux distrubutions as well as freebsd it’s quite probable that the changepass.pl webmin changepassword script is located in different location.
So if you are about to change webmin’s password on other Linux or BSD architecture just either find the script using the gnu find command or use the locate command to search for it and execute the script changing the script location in the foreshown example.
