The Closest Encloser Proof aspect of the DNS protocol (in RFC 5155 when RFC 9276 guidance is skipped) allows remote attackers to cause a denial of service (CPU consumption for SHA-1 computations) via DNSSEC responses in a random subdomain attack, aka the "NSEC3" issue. The RFC 5155 specification implies that an algorithm must perform thousands of iterations of a hash function in certain situations.
Denial of service vulnerability in PowerDNS Recursor allows authoritative servers to be marked unavailable.This issue affects Recursor: through 4.6.5, through 4.7.4 , through 4.8.3.
PowerDNS Recursor up to and including 4.5.9, 4.6.2 and 4.7.1, when protobuf logging is enabled, has Improper Cleanup upon a Thrown Exception, leading to a denial of service (daemon crash) via a DNS query that leads to an answer with specific properties.