BugStat project allows to run regular (i.e. cron based) queries to get more or less detailed bug statistics.
It's requires Bugzillas XML interface and has been tested with Bugzilla Version 2.22.2 only, but should work with any later release as well.
bugstat -u url -l login -p password -s search
-u --url url
The URL to the bugzilla to query
-l --login login
The login name to iuse for the query
-p --password password
Password associated with login
-s --search searchname
Predefined Bugzilla search to use as bese for query