--- vixie-cron_org	2008-07-14 02:36:08.000000000 +0200
+++ vixie-cron	2008-07-07 04:44:02.000000000 +0200
@@ -11,7 +11,7 @@
 
 start() {
 	ebegin "Starting vixie-cron"
-	start-stop-daemon --start --quiet --exec /usr/sbin/cron
+	run-jail vixie-cron start-stop-daemon --start --quiet --exec /usr/sbin/cron
 	eend $?
 }

;
; RSBAC JAIL definition for vixie-cron
; 20080307
;
; Tested by:
; igraltist on gentoo
;
 
""
"0.0.0.0"
(allow-dev-read
 allow-dev-write
 allow-ipc-syslog
 allow-ipc-parent
 )
()
()
(rlimit)

This is execute now:
rsbac_jail  -d -D -y -P -M  rlimit start-stop-daemon  --start --quiet --exec /usr/sbin/cron