Root rights for mailnotify and genwebnotify considered harmful?

By copying and pasting crontab lines such as the one from Question148 or the one in KennethLavrsen's private documentation (http://www.lavrsen.dk/foswiki/bin/view/Kenneth/TWikiOnRedHat) I was tempted into running both mailnotify and genwebnotify as root. In the end, I had the following line in my crontab:

05 3,11,15   * * *   root    ( cd /usr/local/share/foswiki/bin && ../tools/genwebnotify && ../tools/mailnotify -q )

This made Foswiki behave strangely on the first day of each month. Foswiki seems to have some internal log rotating mechanism which causes logYYYYMM.txt and warnYYYYMM.txt to be created once for each month. Now, if no Foswiki action (view, configure, whatever...) was performed before 3:05 a.m. on the frist day of any given month, then the first run of genwebnotify was the first thing that wrote a log message, causing the log file to be created. Since, however, genwebnotify was run as root, the log file was created wih root permissions as well. This, in turn, froze Foswiki since no other component was able to write any logs subsequently.

It took me quite a while to find out that first of all, genwebnotify was causing this trouble and moreover, mailnotify does not (seem to) require root privileges (and neither does genwebnotify).

At first I thought at least mailnotify needed root in order to set the sender of the notification mails appropriately. It turned out, it doesn't, at least in our setup where mails are sent using Net:SMTP. One might still need root privileges if the local sendmail binary is used instead, but I haven't tried.

In the end, the only question remaining is: did I get anything wrong? I don't think there is a bug to be reported because genwebnotify can't tell whether it should drop privileges it was given by accident. So this entry is meant merely as a support for those who shot themselves in the foot just like me...

-- UweSinha - 07 Sep 2009

Already tried to add a

chown www:www ..../logs/log*.txt

to your scripts?

-- OliverKrueger - 09 Oct 2009

Nope -- would have been too easy, wouldn't it?

In fact, I had your solution in mind as a last resort. But I wanted to dig a little deeper (great way to procrastinate a few other things...) and share my findings with the community. If you can think of a better way to do so, I'd love to know.

My actual problem was solved simply by not running mailnotify and genwebnotify as root. Maybe I didn't state that clearly enough. Still I wonder if there are any scenarios in which either of these two scripts does need root privileges. If so, my solution wouldn't work. Otherwise I think that it's closer to the root cause of the problem than cleaning up afterwards using chown.

Feel free to mark my non-question "closed unanswered" if you think this problem is too exotic.

-- UweSinha - 23 Oct 2009

One other cleanup item, since we're "documenting", is that when MailerContrib is run as root, it creates work items as root in foswiki/working/work_areas/MailerContrib

If you then remove root from the crontab as above, and if those aren't chown'd back from root, I find that you get the same notifications over and over as MailerContrib can't edit it's working files.'

-- CraigBowers - 24 Oct 2009

Good catch, Uwe. Please feel free to raise tasks against the MailerContrib and ActionTrackerPlugin to clarify this in the documentation. these cron jobs should always be run as the apache user, and never run as root. Even if it wasn't for this permissions problem, running them as root is a potential hole for a hacker.

-- CrawfordCurrie - 05 Nov 2009

There you go: Foswiki:Tasks.Item2474 (ActionTrackerPlugin), Foswiki:Tasks.Item2473 (MailerContrib), Foswiki:Tasks.Item2472 (BugsContrib).

However, there might be some more of those scripts out there. If they are to be run from cron jobs and write their logs to logYYYYMM.txt, they're probably prone to this kind of behaviour, too.

-- UweSinha - 07 Dec 2009

BTW: Changed the Subject to "Using an extension" "Documentation". Seems more appropriate to me...

-- UweSinha - 07 Dec 2009