all user accounts including root got disabled :(

[PrakashB]

I'm having a CentOS 4.4 X86_64 server. Without any warning all users account including root got disabled. As the server was still logged in as root, i was able to enable all the users account. But for root i couldn't.

Without thinking i rebooted the server and except root, other users can log in to the server. I should've tried to enable root account from the /etc/passwd. But now i realize its too late for that.

Now i want to change from root: x:0:0:root:/root:/bin/false to root: x:0:0:root:/root:/bin/bash. Can anyone guide me to accomplish this or is there any other way to fix this?

Does anyone have answer why all the account got disabled?? If so please help me out.

Thanks.
BP.

[PrakashB]

Here's how i fixed it.

1. I just rebooted the server and boot from CentOS Disc1

2. Went to rescue mode <f5> and entered linux rescue

3. Mounted the filesystem

4. Edited the /etc/passwd to enable root account

5. Restart.

6. Now i can log in with root account.

[Rubberman]

The more important question to be asking is "How did this happen?". It is possible that you have been hacked. Check for new/unknown accounts and enforce a password reset by all users IMMEDIATELY! So, check for rootkits and such that might have been installed if indeed you were pwnd.