This vulnerability in PowerDNS Authoritative allows a malicious primary server to exhaust file descriptors on a secondary server by forwarding DNS update requests, resulting in denial of service. The affected versions are 4.9.0 and 5.0.0. The CVSS 3.1 score is 5.9 (medium), reflecting network attack vector, high attack complexity, no privileges required, no user interaction, unchanged scope, no confidentiality or integrity impact, and high impact on availability. No patch or official fix has been documented, and no known exploits have been reported.

The impact is denial of service caused by resource exhaustion (file descriptors) on PowerDNS secondary servers when interacting with a rogue primary server. This affects service availability but does not compromise data confidentiality or integrity. No active exploitation has been observed.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, administrators should monitor for unusual DNS update traffic patterns from primary servers and consider limiting or validating update requests to mitigate potential resource exhaustion.