An attacker can trigger an assertion failure by requesting crafted DNS records, waiting for them to be inserted into the records cache, then send a query with qtype set to ANY.
Certain DNSSEC aspects of the DNS protocol (in RFC 4033, 4034, 4035, 6840, and related RFCs) allow remote attackers to cause a denial of service (CPU consumption) via one or more DNSSEC responses, aka the "KeyTrap" issue. One of the concerns is that, when there is a zone with many DNSKEY and RRSIG records, the protocol specification implies that an algorithm must evaluate all combinations of DNSKEY and RRSIG records.
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.
A remote attacker might be able to cause infinite recursion in PowerDNS Recursor 4.8.0 via a DNS query that retrieves DS records for a misconfigured domain, because QName minimization is used in QM fallback mode. This is fixed in 4.8.1.
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.
In PowerDNS Authoritative Server before 4.4.3, 4.5.x before 4.5.4, and 4.6.x before 4.6.1 and PowerDNS Recursor before 4.4.8, 4.5.x before 4.5.8, and 4.6.x before 4.6.1, insufficient validation of an IXFR end condition causes incomplete zone transfers to be handled as successful transfers.
An issue has been found in PowerDNS Recursor before 4.1.18, 4.2.x before 4.2.5, and 4.3.x before 4.3.5. A remote attacker can cause the cached records for a given name to be updated to the Bogus DNSSEC validation state, instead of their actual DNSSEC Secure state, via a DNS ANY query. This results in a denial of service for installation that always validate (dnssec=validate), and for clients requesting validation when on-demand validation is enabled (dnssec=process).
In PowerDNS Recursor versions up to and including 4.3.1, 4.2.2 and 4.1.16, the ACL restricting access to the internal web server is not properly enforced.