How is it that once in a while, i lost root access (when i su to root, it gives wrong password). But, when I reboot the server, and su again it works. Then, after a while (a couple of days) it gives the same problem again. Was our server hacked, was it a bug?
First thing that comes to mind: When you su, do you specify the full path (/bin/su) or just the command? If the latter, it's possible you're picking up some other su command (e.g., a shell-script some user created that tries to capture an unsuspecting admin's password). Always specify the full path for su .
I can't think of any other reason, other than bad typing, that su would randomly fail.
- Dave