Technitium DNS Server Denial-of-Service Vulnerability in DNS-over-QUIC

A denial-of-service vulnerability has been identified in Technitium DNS Server versions through 13.2.2. This issue allows remote attackers to permanently disrupt the server's ability to accept new DNS-over-QUIC connections by causing unhandled exceptions in the listener threads.

Impact

Exploitation of this vulnerability causes a denial-of-service condition, where the DNS server stops accepting new DNS-over-QUIC connections.

Reproduction

The vulnerability can be reproduced by sending DNS-over-QUIC requests that trigger unhandled exceptions in the server's listener threads. This can be done by exploiting specific conditions in the DNS-over-QUIC protocol handling, causing the server to fail in processing the requests and leading to a service interruption.

Remediation

Users can upgrade to Technitium DNS Server version 13.3 or later, where this vulnerability has been fixed.