CVE-2024-10085 in EcoStruxure Modicon Communication Server
Summary
by MITRE • 09/01/2026
CWE-770: Allocation of Resources Without Limits or Throttling vulnerability exists that could cause denial of service of the OPC UA communication platform when a large number of OPC UA requests are sent to the platform.
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Analysis
by VulDB Data Team • 09/01/2026
The vulnerability identified as CWE-770, Allocation of Resources Without Limits or Throttling, represents a critical architectural flaw within the specified OPC UA communication platform that directly compromises system availability and reliability. This class of weakness occurs when an application fails to impose appropriate constraints on resource consumption during request processing, allowing external actors to exhaust finite system resources such as memory, CPU cycles, or connection handles. In the context of industrial control systems and enterprise automation environments where OPC UA is frequently deployed for secure machine-to-machine communication, this flaw transforms a standard operational load into a potential denial-of-service vector. The absence of rate limiting mechanisms means that the platform does not distinguish between legitimate high-volume traffic from authorized clients and malicious flooding attempts designed to overwhelm the server infrastructure.
From a technical perspective, the core issue lies in the lack of input validation regarding request frequency and volume before resource allocation occurs. When an attacker or misconfigured client sends a large number of OPC UA requests simultaneously, the platform allocates new threads, memory buffers, or network sockets for each incoming connection without checking against predefined thresholds. This unbounded growth in active connections leads to resource exhaustion, causing the server to become unresponsive to all subsequent legitimate requests. The operational impact is severe, as it can halt critical industrial processes that rely on real-time data exchange and control commands via OPC UA protocols. Such disruptions can lead to significant downtime, production losses, and potential safety hazards if automated systems fail to respond appropriately during a service outage.
This vulnerability aligns with the MITRE ATT&CK technique T1499, Endpoint Denial of Service, specifically under sub-techniques related to resource exhaustion through application layer flooding. By exploiting this flaw, an adversary can effectively disable critical infrastructure components without needing elevated privileges or complex exploit code, simply by generating sufficient traffic volume. The simplicity of the attack makes it particularly dangerous in environments where DDoS mitigation strategies are not explicitly configured for OPC UA endpoints. Furthermore, because OPC UA often operates on non-standard ports within internal networks, traditional perimeter-based defenses may fail to detect or mitigate this type of application-layer abuse, leaving the platform exposed to sustained availability attacks that degrade performance until manual intervention is required.
To mitigate this risk, it is essential to implement robust rate limiting and throttling mechanisms at both the network and application layers. Network-level controls should include firewall rules that restrict the number of concurrent connections per source IP address and drop packets exceeding defined thresholds for OPC UA traffic. At the application level, developers must enforce strict limits on request processing rates, ensuring that resources are allocated only up to a safe maximum capacity. Additionally, implementing connection pooling with idle timeout settings can help manage resource usage more efficiently by reusing existing connections rather than creating new ones for every request. Regular load testing and stress analysis should be conducted to identify breaking points in the system's handling of high-volume traffic, allowing administrators to tune these limits appropriately before deployment in production environments.