Recently one of my Gentoo linux servers, which has been working happily for quite a few years suddenly stopped responding to BASH commands that I commonly issue it. Very basic commands such as rc-update, or check my iptables configuration status. Now after a few minutes of sleuthing, I discovered that it was because my $PATH variable no longer referenced /sbin/ or /usr/sbin/. Now this seemed like a trivial fix, but strange that it should happen out of the blue like that.
Now where this is where it gets a little strange: I just logged into the OTHER Gentoo server located on the same facility, and suddenly it has the same issue. Both /sbin/ and /usr/sbin are gone from the $PATH env variable. I am the only person in the wheel group, and the only person with even sudo access to either of these systems. One of them is accessible via SSH, but there is no record of anyone su'ing to root or sudoing at a time when I know it wasnt me. And I certanly can not think of anything else that could have changed this.
I guess I have two questions here:
1) Is it possible that this is some sort of breakin where someone did something malicious and this is just a symptom of what they have done? If so what should I look for.
2) If this is benign, then can anyone suggest a permanent fix for this, and more importantly a reasonable explanation of how this could happen to a server that is not being modified by anyone with permissions to change system files?
Now I use Gentoo for servers at my house as well, a multitude of desktops, and this laptop I'm writing this on right now. None of these systems have experienced similar issues, some have been updated, others have not. But none have experienced this sort of problem. This is what makes me suspicious of the two servers that have experienced this issue a month or so apart.
Thank you in advance for any help you can provide me with