| Description |
A denial of service issue has been found in PowerDNS Authoritative Server and PowerDNS Recursor before 4.6.1.
IXFR usually exchanges only the modifications between two versions of a zone, but sometimes needs to fall back to a full transfer of the current version. When IXFR falls back to a full zone transfer, an attacker in position of man-in-the-middle can cause the transfer to be prematurely interrupted. This interrupted transfer is mistakenly interpreted as a complete transfer, causing an incomplete zone to be processed. For the Authoritative Server, IXFR transfers are not enabled by default. The Recursor only uses IXFR for retrieving RPZ zones. An incomplete RPZ transfer results in missing policy entries, potentially causing some DNS names and IP addresses to not be properly intercepted. |