Powerdns ≫ Recursor

This fix provides extra hardening for the 5.4.x branch by doing extra validation of incoming answers from authoritative servers.

Spoofing replies to Recursor might mark an IP of an authoritative server as not supporting EDNS, causing valdiation of DNSSEC records served by that server to fail.

An invalid zone might pass ZONEMD validation while it should not. This is only relevant if ZoneToCache is configured with ZONEMD validation.

Incomplete validation of the SOA record present in a catalog zone might lead to a crash.

A malicious authoritative server can send a crafted zone via the ZoneToCache function that leads to a crash of the Recursor due to insuffcient input validation.

ECS zero scoped answers are stored in the packet cache while they should not. This impacts only configurations that have ECS enabled;

A malicious authoritative server can send a crafted zone via the ZoneToCache function that leads to cache poisoning.

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 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.

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.