CVE-2025-9166 in ControlLogix 5580
Summary
by MITRE • 09/09/2025
A denial-of-service security issue exists in the affected product and version. The security issue stems from the controller repeatedly attempting to forward messages. The issue could result in a major nonrecoverable fault on the controller.
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Analysis
by VulDB Data Team • 10/21/2025
The vulnerability identified as CVE-2025-9166 represents a critical denial-of-service condition within the affected product architecture that fundamentally undermines system stability and operational continuity. This security flaw manifests through a specific behavioral pattern where the controller engages in repetitive message forwarding operations that ultimately overwhelm system resources and trigger catastrophic failures. The vulnerability operates at the core of the system's message handling mechanisms, creating a recursive loop that consumes excessive computational cycles and memory resources, leading to complete system incapacitation.
The technical root cause of this vulnerability lies in the controller's inadequate error handling and resource management protocols during message processing operations. When the system encounters conditions that would normally trigger graceful degradation or error recovery mechanisms, the controller instead enters an infinite loop of message forwarding attempts without proper termination conditions or resource consumption limits. This behavior directly maps to CWE-835, which specifically addresses infinite loops in software systems, where the lack of proper loop termination conditions leads to resource exhaustion and system failure. The controller's failure to implement proper bounds checking and resource monitoring creates an exploitable condition where malicious actors can trigger the vulnerability through carefully crafted message sequences.
The operational impact of CVE-2025-9166 extends far beyond simple service disruption, as the vulnerability can result in complete system incapacitation that may require extensive recovery procedures and potentially hardware replacement. When the controller reaches its resource exhaustion threshold, it typically manifests as system crashes, complete service outages, and potential data loss scenarios that can persist for extended periods requiring manual intervention and system reset procedures. The nonrecoverable nature of the fault means that once triggered, the system cannot automatically recover without operator intervention, creating significant operational risk for mission-critical deployments. This vulnerability particularly affects environments where continuous system availability is paramount, such as industrial control systems, network infrastructure, or real-time processing environments where downtime can result in substantial financial losses or safety hazards.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1499.004 which describes network disruption attacks targeting system availability. The flaw can be exploited through various attack vectors including malformed message injection, network traffic manipulation, or even social engineering approaches that cause the controller to process specific message patterns that trigger the problematic forwarding loop. Organizations should implement robust monitoring and alerting systems to detect unusual message processing patterns that could indicate exploitation attempts. Mitigation strategies should focus on implementing rate limiting mechanisms, message validation protocols, and resource consumption monitoring to prevent the controller from entering the problematic forwarding loop. Additionally, defensive measures including regular system updates, network segmentation, and implementing redundant controller systems can significantly reduce the impact of this vulnerability. The vulnerability also underscores the importance of proper software design principles including fail-safe mechanisms, proper resource management, and comprehensive testing of error conditions to prevent similar issues in future system deployments.