CVE-2026-67872 in S2OPC
Summary
by MITRE • 08/06/2026
An issue in Systerel S2OPC 1.7.3 allows a remote attacker to cause a denial of service via the event monitored-item queue resize handling
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Analysis
by VulDB Data Team • 08/06/2026
The vulnerability in Systerel S2OPC 1.7.3 represents a critical denial of service weakness that arises from improper handling of event monitored-item queue resizing operations within the OPC UA communication framework. This issue affects the software's ability to dynamically adjust memory allocation for event monitoring processes, creating a potential attack vector that remote adversaries can exploit to disrupt normal system operations. The flaw exists in the underlying queue management mechanism responsible for handling monitored items that track events generated by OPC UA servers and clients.
The technical implementation of this vulnerability stems from inadequate bounds checking and memory management during dynamic queue resizing operations. When the system processes event notifications or monitored item updates, it attempts to resize internal data structures to accommodate varying loads of event data. However, the software fails to properly validate input parameters or handle edge cases during these resize operations, leading to potential buffer overflows, memory corruption, or allocation failures that ultimately result in application termination or complete service unavailability.
From an operational perspective, this vulnerability poses significant risks to industrial control systems and automation environments where Systerel S2OPC is deployed. The remote attack capability means that adversaries can exploit this weakness from outside the local network without requiring physical access or prior authentication credentials. This makes it particularly dangerous in SCADA systems, manufacturing environments, and other critical infrastructure applications where continuous operation is essential for safety and productivity. The impact extends beyond simple service disruption to potentially compromising operational continuity in mission-critical deployments.
The vulnerability aligns with CWE-129 which addresses insufficient input validation and CWE-787 which covers out-of-bounds write operations. From an ATT&CK framework perspective, this represents a denial of service technique that can be categorized under T1499.3 - Endpoint Denial of Service, where adversaries target application-level vulnerabilities to render systems non-operational. The attack surface is particularly concerning given the widespread use of OPC UA protocols in industrial environments and the limited visibility into such protocol implementations within operational technology networks.
Organizations should implement immediate mitigations including applying the vendor-provided patches or updates that address the queue resizing logic, implementing network segmentation to limit exposure of affected systems, and deploying intrusion detection systems that can monitor for anomalous queue manipulation patterns. Additionally, system administrators should consider reducing the number of monitored items where possible, implementing proper resource limits on queue operations, and establishing robust monitoring procedures to detect early signs of queue-related failures. The remediation process should include thorough testing of updated configurations to ensure that legitimate event processing continues to function correctly while eliminating the vulnerability surface that adversaries can exploit for denial of service attacks.