Unspecified vulnerability in PowerDNS Recursor (aka pdns_recursor) 3.6.x before 3.6.1 allows remote attackers to cause a denial of service (crash) via an unknown sequence of malformed packets.

The resolver in PowerDNS Recursor (aka pdns_recursor) 3.3 overwrites cached server names and TTL values in NS records during the processing of a response to an A record query, which allows remote attackers to trigger continued resolvability of revoked domain names via a "ghost domain names" attack.