CVE-2024-8418 is a vulnerability identified in Aardvark-dns versions 1.12.0 and 1.12.1, where the DNS server processes TCP DNS queries serially rather than concurrently. This design flaw allows an attacker to open a TCP connection and keep it open indefinitely, effectively consuming server resources and preventing the server from processing other incoming DNS queries. The result is a Denial of Service (DoS) condition where legitimate users experience DNS query timeouts and service unavailability. The vulnerability does not impact confidentiality or integrity but severely affects availability. It requires no privileges or user interaction and can be exploited remotely over the network. The CVSS v3.1 score is 7.5 (high), reflecting the ease of exploitation and significant impact on availability. No patches or vendor mitigations are currently linked, and no known exploits have been reported in the wild as of the publication date. This vulnerability highlights the risks of synchronous TCP query handling in DNS servers and underscores the need for concurrent processing or connection limits to prevent resource exhaustion attacks.

The primary impact of CVE-2024-8418 is the disruption of DNS services due to Denial of Service caused by resource exhaustion. DNS is a critical infrastructure component for virtually all internet-connected organizations, and its unavailability can lead to widespread service outages, inability to resolve domain names, and interruption of business operations. Organizations using affected versions of Aardvark-dns may experience degraded network performance, loss of connectivity to internal and external resources, and potential cascading failures in dependent systems. This can affect web services, email delivery, cloud applications, and any service relying on DNS resolution. The attack can be launched remotely without authentication, increasing the risk of widespread exploitation. Although no data confidentiality or integrity issues arise, the availability impact alone can cause significant operational and financial damage, especially for enterprises, ISPs, and critical infrastructure providers.

To mitigate CVE-2024-8418, organizations should first check if they are running Aardvark-dns versions 1.12.0 or 1.12.1 and upgrade to a patched version once available. In the absence of an official patch, administrators should implement network-level controls such as rate limiting TCP connections to the DNS server and setting aggressive TCP connection timeouts to prevent indefinite open connections. Deploying firewall rules or intrusion prevention systems (IPS) to detect and block suspicious long-lived TCP DNS connections can reduce exposure. Additionally, consider configuring DNS servers to handle TCP queries concurrently or deploying load balancers to distribute query loads and isolate resource exhaustion. Monitoring DNS server performance and connection metrics can help detect early signs of exploitation. Finally, segregate DNS infrastructure and restrict access to trusted networks where possible to limit attack surface.