CVE-2024-48077 is a denial-of-service vulnerability affecting nanomq version 0.22.7, a lightweight MQTT broker commonly used in IoT and messaging applications. The flaw stems from improper handling of incoming data packets in the recv-q queue, where an attacker can send specially crafted requests that cause the queue to grow indefinitely. This growth leads the nanomq broker process to enter a deadlock state, rendering it incapable of processing legitimate messages or maintaining normal operations. The vulnerability is classified under CWE-400 (Uncontrolled Resource Consumption) and CWE-833 (Deadlock). The CVSS v3.1 score is 7.5, reflecting high severity due to the network attack vector, lack of required privileges or user interaction, and the impact limited to availability. No confidentiality or integrity compromise occurs. The vulnerability can be exploited remotely by any unauthenticated attacker capable of sending network packets to the nanomq broker. Currently, there are no known exploits in the wild, and no official patches have been released. The lack of patch availability necessitates interim mitigations to prevent exploitation. Given nanomq's role in IoT and messaging infrastructures, successful exploitation could disrupt critical data flows and automation processes.

For European organizations, the primary impact is service disruption due to denial of service on nanomq brokers. This can affect industries relying on real-time messaging and IoT data transmission, such as manufacturing, energy, transportation, and smart city infrastructure. Disruptions could lead to operational downtime, loss of productivity, and potential safety risks in automated environments. Since nanomq is often deployed in edge computing and industrial IoT scenarios, availability issues could cascade into broader system failures. The lack of confidentiality or integrity impact reduces risks related to data breaches, but availability loss in critical infrastructure could have significant economic and safety consequences. Organizations with large-scale IoT deployments or those integrating nanomq brokers into their communication stacks are at higher risk. The absence of known exploits in the wild provides a window for proactive mitigation, but the high severity score underscores the need for urgent attention.

Until an official patch is released, European organizations should implement network-level protections such as firewall rules to restrict access to nanomq brokers only to trusted sources. Deploy rate limiting and traffic shaping to control the volume of incoming packets and prevent recv-q queue saturation. Monitor the nanomq broker's recv-q queue length and process responsiveness to detect early signs of exploitation attempts. Consider deploying intrusion detection systems (IDS) with custom signatures to identify anomalous packet patterns targeting nanomq. If feasible, isolate nanomq brokers within segmented network zones to limit exposure. Regularly review and update incident response plans to include scenarios involving nanomq DoS attacks. Engage with nanomq maintainers or vendors to obtain patches or updates as soon as they become available. Additionally, evaluate alternative MQTT brokers with more robust DoS protections for critical deployments.