Insufficient input validation of internal webserver
An attacker can send a web request that causes unlimited memory allocation in the internal web server, leading to a denial of service. The internal web server is disabled by default.
Concurrent modification of RPZ data can lead to denial of servce
Having many concurrent transfers of the same RPZ can lead to inconsistent RPZ data, use after free and/or a crash of the recursor. Normally concurrent transfers of the same RPZ zone can only occur with a malfunctioning RPZ provider.
Insufficient input validation of internal webserver
An attacker can send a web request that causes unlimited memory allocation in the internal web server, leading to a denial of service. The internal web server is disabled by default.
Unbounded memory allocation by internal web server
An attacker can send a web request that causes unlimited memory allocation in the internal web server, leading to a denial of service. The internal web server is disabled by default.
If you use the zoneToCache function with a malicious authoritative server, an attacker can send a zone that result in a null pointer dereference, caused by a missing consistency check and leading to a denial of service.
An RPZ sent by a malicious authoritative server can result in a null pointer dereference, caused by a missing consistency check and leading to a denial of service.
A Recursor configured to send out ECS enabled queries can be sensitive to spoofing attempts
An attacker spoofing answers to ECS enabled requests sent out by the Recursor has a chance of success higher than non-ECS enabled queries.
The updated version include various mitigations against spoofing attempts of ECS enabled queries by chaining ECS enabled requests and enforcing stricter validation of the received answers.
The most strict mitigation done when the new setting outgoing.edns_subnet_harden (old style name edns-subnet-harden) is enabled.
A crafted zone can lead to an illegal memory access in the PowerDNS Recursor
An attacker can publish a zone containing specific Resource Record Sets. Processing and caching results for these sets can lead to an illegal memory accesses and crash of the Recursor, causing a denial of service.
The remedy is: upgrade to the patched 5.2.1 version.
We would like to thank Volodymyr Ilyin for bringing this issue to our attention.
Crafted responses can lead to a denial of service due to cache inefficiencies in the Recursor
An attacker can publish a zone containing specific Resource Record Sets.
Repeatedly processing and caching results for these sets can lead to a
denial of service.
Crafted responses can lead to a denial of service in Recursor if recursive forwarding is configured
A crafted response from an upstream server the recursor has been configured to forward-recurse to can cause a Denial of Service in the Recursor. The default configuration of the Recursor does not use recursive forwarding and is not affected.
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.