Login fails on Webmin

[s34n]

Binary package hint: sudo

Performed clean install of ubuntu-11.04-beta1-server-amd64 with only ssh and LAMP.
Installed Webmin version 1.540 (http://sourceforge.net/projects/webadmin/).
Opened web browser from another machine on local network and connected to webmin server on port 10000.
Entered my ubuntu user name and password.
Received this from Webmin server: Login failed. Please try again.
This happens every time with known good user name and password until it blocks the connecting IP address for multiple failed attempts.
Tested with the previous version of Webmin and have same problem.
I forced a downgrade of sudo package from 1.7.4p4-5ubuntu5 to 1.7.2p7-1ubuntu2.1 and thereafter login to Webmin server was successful.

[Tim Nelson (iamtim)]

I am having exactly the same problem. Login fails despite known good user and password. I'm not going to downgrade sudo, however. It isn't worth accessing webmin.

[Alexander Karatarakis (alexkaratarakis)]

Still an issue with current development version of 11.04, which is probably the final one since release is in two days.

[John c (redbarnroad)]

Solved same issue with Mythbuntu 11.04 - The default webmin user was root, with an unknown password. This did not match my username and password set during install!
Ran this script to set it;
sudo /usr/share/webmin/changepass.pl /etc/webmin root "your-password"
Once in to the web, I added a new webmin user, to match my logon name. Hope this helps someone get it fixed!

[hopugop (guilhy-nogueira)]

John c's tip solved the problem to me. I'm using Ubuntu 11.04.

[Evan Adelman (evanadelman)]

ditto - ran into this problem as well. has anyone tried a higher version of sudo instead of downgrading?

[Philip Argent (pargent)]

I also had this issue.
I just created a password for root using "sudo passwd root"
logged into webmin with root
created a new account in webmin
logged out of webmin
logged into webmin with the new account
disabled root again using "sudo passwd -l root"

[techrockstar (techrockstar)]

sudo /usr/share/webmin/changepass.pl /etc/webmin root "your-password"

from John C works!

[Jefe (pgouaillier)]

I discovered that connecting as sudoers works if the user is directly referred in the sudoers file. Normally, users are sudoers by being member of the group admin.

You can test this, just by copying the line:

%admin ALL=(ALL) ALL

and replace "%admin" by the user id.

of course, this does not constitute a solution but I thought this would help troubleshooting.

[Cas (calumlind)]

Just encountered this exact issue and can confirm Jefe's much simpler workaround works. :)

[Steve Langasek (vorlon)]

I don't see anything here that describes a bug in sudo; webmin seems to simply not support thedefault sudo setup included in Ubuntu. Sounds like something you'll need to take up with webmin upstream.

[Erik Zaki (eriksh7)]

sudo /usr/share/webmin/changepass.pl /etc/webmin root "your-password" solved it for me as well
Ubuntu 14.04.5 - Webmin 1.831