CVE-2026-75345 in OpENer
Summary
by MITRE • 10/09/2026
OpENer v2.3.0 / commit 76b95cf contains an out-of-bounds read in the unconnected explicit messaging path. This allows a remote attacker to cause a denial of service.
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Analysis
by VulDB Data Team • 10/09/2026
The vulnerability identified within OpENer version 2.3.0, specifically associated with commit hash 76b95cf, represents a critical memory safety flaw located in the implementation of the unconnected explicit messaging path. This component is responsible for handling incoming EtherNet/IP messages that do not require an established connection session between the client and the server. The core technical defect is classified as an out-of-bounds read, which occurs when the application attempts to access memory locations beyond the allocated buffer boundaries during the parsing or processing of these specific message types. This type of error typically arises from insufficient validation of input data lengths against the actual size of the destination buffers, allowing a remote attacker to trigger unauthorized memory reads by crafting maliciously sized packets that exploit this boundary condition.
From an operational perspective, the primary impact of this vulnerability is a denial of service against the affected industrial automation device or software stack. Because out-of-bounds read errors often lead to undefined behavior in C-based systems like OpENer, the immediate consequence is typically a segmentation fault or core dump that causes the application process to crash abruptly. In an industrial control environment where continuous availability is paramount, such crashes can result in significant downtime, halting production lines and disrupting critical infrastructure operations. While out-of-bounds reads are primarily associated with information disclosure if sensitive data resides in adjacent memory regions, the specific manifestation described here emphasizes service disruption rather than data leakage, highlighting the instability introduced by improper memory management practices within the messaging handler.
This vulnerability aligns closely with Common Weakness Enumeration identifier CWE-125, which defines out-of-bounds read errors resulting from invalid pointer arithmetic or lack of bounds checking on array accesses. Furthermore, in the context of the MITRE ATT&CK framework for industrial control systems and general network attacks, this flaw facilitates actions categorized under Denial of Service techniques that target application availability through resource exhaustion via malformed inputs. The attack vector is remote, meaning an adversary does not need physical access or prior authentication to exploit this weakness, provided they can reach the network segment hosting the vulnerable OpENer instance. This accessibility significantly increases the risk profile for devices deployed in less secure industrial networks where perimeter defenses may be lax.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. The most effective solution is to apply the vendor-provided patch that addresses commit 76b95cf, ensuring that the source code includes rigorous bounds checking before any memory access operations are performed within the unconnected explicit messaging handler. Developers should implement strict input validation routines that verify packet lengths against buffer capacities prior to processing. Additionally, deploying network-level intrusion detection systems configured to identify anomalous EtherNet/IP traffic patterns can provide a layer of defense by blocking malformed packets before they reach the vulnerable application logic. For organizations unable to patch immediately, isolating affected devices in segregated virtual local area networks with strict access control lists serves as a viable compensatory control to limit exposure to potential attackers.