According to this, certain DNS servers are still "unsafe"

"The name server answers recursive queries for 3rd parties (such as
DNSCheck). By making a recursive query to a name server that provides
recursion, an attacker can cause a name server to look up and cache
information contained in zones under their control. Thus the victim
name server is made to query the attackers malicious name servers,
resulting in the victim caching and serving bogus data."

This seems to affect at least the currently released/patched named.nlm