CVE-2024-8418 is a vulnerability affecting 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 blocking the processing of other incoming DNS queries. Because DNS is a critical service for network name resolution, this leads to a Denial of Service (DoS) condition where legitimate users experience timeouts and inability to resolve domain names. The vulnerability requires no authentication or user interaction and can be exploited remotely, increasing its risk profile. The CVSS 3.1 score of 7.5 reflects high severity due to the impact on availability and ease of exploitation. While no public exploits have been reported yet, the vulnerability is recognized by authoritative sources such as Red Hat and CISA. The root cause is the lack of concurrent handling of TCP DNS queries, which is a fundamental architectural limitation in the affected versions of Aardvark-dns. This flaw can be mitigated by patching the software to versions that handle TCP queries concurrently or by implementing network-level controls to limit the duration and number of TCP connections to the DNS server.

For European organizations, the impact of CVE-2024-8418 can be significant, especially for those relying on Aardvark-dns in critical infrastructure, enterprise networks, or service provider environments. A successful DoS attack can disrupt DNS resolution, leading to widespread service outages affecting web access, email delivery, internal applications, and cloud services. This can result in operational downtime, loss of productivity, and potential financial losses. Additionally, DNS outages can impair security monitoring and incident response capabilities that depend on DNS lookups. The disruption of DNS services can also affect compliance with regulatory requirements for service availability and incident management. Organizations with high dependency on DNS availability, such as financial institutions, healthcare providers, and government agencies, face elevated risks. The vulnerability’s remote exploitability and lack of required privileges increase the likelihood of exploitation attempts, making timely mitigation critical.

1. Monitor vendor advisories and apply patches or updates to Aardvark-dns as soon as they become available that address this vulnerability. 2. Implement network-level protections such as TCP connection timeouts and limits on the number of simultaneous TCP connections to the DNS server to prevent resource exhaustion. 3. Deploy rate limiting and connection throttling mechanisms on firewalls or load balancers in front of DNS servers to detect and block abnormal connection patterns. 4. Consider using DNS server software that supports concurrent processing of TCP queries or load balancing DNS queries across multiple servers to reduce single points of failure. 5. Monitor DNS server logs and network traffic for signs of prolonged TCP connections or unusual query patterns indicative of exploitation attempts. 6. Incorporate DNS redundancy and failover strategies to maintain service availability during attack conditions. 7. Conduct regular security assessments and penetration tests focusing on DNS infrastructure resilience. 8. Educate network operations teams about this vulnerability and response procedures to quickly identify and mitigate attacks.