An attacker can send specially crafted replies that cause the PowerDNS Recursor to dereference a null pointer because the system lacks a consistency check. This flaw triggers a denial of service in the affected server. The weakness originates from insufficient validation of cookie reply data, enabling a null pointer dereference that crashes the process.

The vulnerability affects the PowerDNS Recursor application. Current version information is not provided in the advisory, and affected releases are not specified, so all deployed instances of PowerDNS Recursor that have not been updated per the official advisory may be susceptible.

The flaw has a CVSS score of 5.9, indicating moderate severity. The EPSS score is not available, so no estimate of exploitation frequency is provided. It is not listed in the CISA KEV catalog. Based on the description, the attack vector is likely network-based, requiring an attacker to send crafted replies to a running Recursor instance. Successful exploitation would result in process termination and denial of service for clients relying on that server.