When api-config-dir is set to a non-empty value, which is not the case by default, the API in PowerDNS Recursor 4.x up to and including 4.0.6 and 3.x up to and including 3.7.4 allows an authorized user to update the Recursor's ACL by adding and removing netmasks, and to configure forward zones. It was discovered that the new netmask and IP addresses of forwarded zones were not sufficiently validated, allowing an authenticated user to inject new configuration directives into the Recursor's configuration.

commonstartup.cc in PowerDNS (aka pdns) Authoritative Server before 2.9.22.5 and 3.x before 3.0.1 allows remote attackers to cause a denial of service (packet loop) via a crafted UDP DNS response.

PowerDNS Recursor before 3.1.6 does not always use the strongest random number generator for source port selection, which makes it easier for remote attack vectors to conduct DNS cache poisoning. NOTE: this is related to incomplete integration of security improvements associated with addressing CVE-2008-1637.

Buffer overflow in PowerDNS Recursor before 3.1.7.2 allows remote attackers to cause a denial of service (daemon crash) or possibly execute arbitrary code via crafted packets.

Unspecified vulnerability in PowerDNS Recursor before 3.1.7.2 allows remote attackers to spoof DNS data via crafted zones.

An issue has been found in the API component of PowerDNS Authoritative 4.x up to and including 4.0.4 and 3.x up to and including 3.4.11, where some operations that have an impact on the state of the server are still allowed even though the API has been configured as read-only via the api-readonly keyword. This missing check allows an attacker with valid API credentials to flush the cache, trigger a zone transfer or send a NOTIFY.