The asterisk character ("*") is allowed in DNS zone files, where
it is most commonly present as a wildcard at a terminal node of
the Domain Name System graph. However, the RFCs do not require
and BIND does not enforce that an asterisk character be present
only at a terminal node.
A problem can occur when an asterisk is present in an empty
non-terminal location within the DNS graph. If such a node exists,
after a series of queries, named can reach an inconsistent state
that results in the failure of an assertion check in rbtdb.c,
followed by the program exiting due to the assertion failure.