Cent OS 6.10 - Cannot login as root despite the password being correct

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kayul
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Joined: 2021/01/27 07:00:37

Cent OS 6.10 - Cannot login as root despite the password being correct

Post by kayul » 2021/01/27 07:16:10

Hello Centos,

I have a CentOS 6.10 system and having this weird problem

A few days ago when I try to login as root at the console, I get an "Incorrect Password" error message. I'm very sure the password is correct because i have login with the same password ever since I installed the system

To get back the root password i followed the reset instruction here https://wiki.centos.org/TipsAndTricks/ResetRootPassword

Today the problem is back where i can't login to root with the correct password.

Its like there is a setting somewhere where the password is reset

How do I solve this problem ? Any help is much appreciated

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TrevorH
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Re: Cent OS 6.10 - Cannot login as root despite the password being correct

Post by TrevorH » 2021/01/27 10:29:01

Either something or someone is changing it for you or you have a keyboard problem for example, keyboard layout mapping can radically alter which characters are sent when keys are pressed - for example, US keyboard has an @ where a UK keyboard has an " character.
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

kayul
Posts: 4
Joined: 2021/01/27 07:00:37

Re: Cent OS 6.10 - Cannot login as root despite the password being correct

Post by kayul » 2021/01/28 00:05:04

Hi thanks Trevor

For now i am the only one who is managing the server. Actually the server is attached to a rack mount keyboard and I have another server with Centos 6.10 installed using the same keyboard but not having this problem

I have a simple password with numbers and letters combination without symbol

i made search and found these topics but they are using cent os 4 and cent os 7, what is the equivalent solution for centos 6 ?

viewtopic.php?t=35273
viewtopic.php?t=60719

By the way, where do i can find the log error message in centos 6.10 ?

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TrevorH
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Re: Cent OS 6.10 - Cannot login as root despite the password being correct

Post by TrevorH » 2021/01/28 14:52:55

The first of those posts is not applicable to you. The second one would only be applicable if you manipulate /etc/shadow or /etc/passwd from a system that does not use selinux. If neither of those is the case then that won't apply either.

When you have the problem, examine your log files after and see what is logged about the problem. Start with /var/log/secure and see if it tells you what is wrong.
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

kayul
Posts: 4
Joined: 2021/01/27 07:00:37

Re: Cent OS 6.10 - Cannot login as root despite the password being correct

Post by kayul » 2021/01/30 08:45:37

Hi thanks again Trevor

in /var/log/secure, i saw many possible break in attempt and failed login by unknown user using ssh,

Just to be safe i format the server, since its an old server i planned to install centos 6.10 again later some time

im actually new on this thing any advice to prevent this thing from happening again ?

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TrevorH
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Re: Cent OS 6.10 - Cannot login as root despite the password being correct

Post by TrevorH » 2021/01/30 13:31:09

Lots of login attempts in /var/log/secure is not necessarily a sign of compromise. It's a sign that you have your ssh port open to the world and that the skript kiddies have found it and are trying to brute force it but if you security is otherwise OK, they probably didn't get in. Do you use ssh keys and have password logins disabled? If so then you're probably safe. If not then do you have an adequately secure password on the root account? Did anyone get in as a normal user and then attempt to escalate their privileges?
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

kayul
Posts: 4
Joined: 2021/01/27 07:00:37

Re: Cent OS 6.10 - Cannot login as root despite the password being correct

Post by kayul » 2021/01/30 15:15:55

So far before i discovered the log, ive been using it with out problem except the password problem and i didnt see any other unfamilliar account

I think my password is not secure enough ..ill take note that for my next install and changed in my other servers
Thank you very much for the input

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