When my non-sudo account tries to run a sudo command:
nonsudo@Hairy14:$ sudo hello
An incident is reported:
[sudo] password for nonsudo:
nonsudo is not in the sudoers file. This incident will be reported.
I'm guessing it's not really Father Christmas, so who is it reported to (or where) and how can I access it?
(From xkcd, by Randall Munroe)
The Title of the image might give us a clue:
What does
/var/spool/mail/root
contain? Uhh, for me nothing as a normal user:And the same with
sudo
. For me, there is no/var/spool/mail/root
It turns out, Ubuntu is different - by default root's mail goes to
/dev/null
, or the black hole in your computer.To find our logs, we need to look in
And lo and behold, a
sudo cat
gives us this line:Note that sometimes (e.g. if your account has no password, is disabled) it will simply not let you run the command - but it will still be reported in the same way:
Note that there is a lot of other text along with the "naughty" reports. You may need to grep.
The journalctl method
One method involves looking through the
journalctl
output.journalctl /usr/bin/sudo
will list all messages related to that specific executable path, and the reported incident will be highlighted in a nice, noticeable red color like so:journalctl -f /usr/bin/sudo
will show only the most recent journal entries, and continuously print new entries as they are appended to the journal. It's only helpful if the reported incident has happened just recently.GNOME Logs
Another way to find such incidents is to use the default Logs application, which is installed by default on recent Ubuntu releases. A short screencast showcasing how it can be done through GNOME Logs: https://webm.red/view/yc0w.webm
It lacks the highlighting of the journalctl, though.