CVE-2024-48077 is a vulnerability identified in nanomq version 0.22.7, a lightweight MQTT broker commonly used in IoT and messaging applications. The flaw allows an unauthenticated remote attacker to send crafted requests that cause the recv-q queue, which buffers incoming data packets, to grow indefinitely. This leads to a deadlock condition within the nanomq broker process, effectively halting its ability to process legitimate messages and resulting in a Denial of Service (DoS). The vulnerability stems from improper handling of incoming data queues and inadequate synchronization mechanisms, as indicated by its association with CWE-400 (Uncontrolled Resource Consumption) and CWE-833 (Deadlock). The CVSS 3.1 base score of 7.5 reflects a high severity due to the network attack vector, no required privileges or user interaction, and a direct impact on availability without affecting confidentiality or integrity. No patches or fixes are currently listed, and no active exploitation has been reported, but the potential for disruption in environments relying on nanomq brokers is significant. The vulnerability is particularly concerning for deployments in critical infrastructure and industrial IoT where continuous message flow is essential.

For European organizations, the primary impact of CVE-2024-48077 is the disruption of services relying on nanomq brokers, which are often integral to IoT ecosystems, industrial automation, and real-time messaging infrastructures. A successful attack can cause complete service outages, affecting operational continuity, data collection, and control systems. This can lead to downtime in manufacturing plants, smart city applications, and other critical services, potentially causing financial losses and safety risks. Since the vulnerability does not compromise data confidentiality or integrity, the main concern is availability. The ease of exploitation without authentication increases the risk of widespread attacks, especially in environments with exposed or poorly segmented nanomq services. European sectors with heavy IoT adoption, such as automotive, manufacturing, and energy, may face increased operational risks if this vulnerability is exploited.

Given the absence of an official patch, European organizations should implement immediate mitigations to reduce exposure. These include deploying network-level controls such as firewalls and intrusion prevention systems to restrict access to nanomq brokers only to trusted sources. Implement rate limiting and traffic shaping to prevent excessive or malformed requests from overwhelming the recv-q queue. Monitor nanomq process metrics closely, especially queue sizes and process responsiveness, to detect early signs of attack. Where possible, isolate nanomq brokers within segmented network zones to limit attack surface. Consider deploying application-layer gateways or MQTT proxies that can validate and filter incoming requests before they reach nanomq. Organizations should also engage with nanomq maintainers or vendors for updates and patches and plan for timely deployment once available. Regular security assessments and penetration testing focused on messaging infrastructure can help identify exposure to this and similar vulnerabilities.