CVE-2026-75353 in OpENer
Summary
by MITRE • 10/09/2026
OpENer v2.3/ commit 76b95cf, contains an out-of-bounds read in the server-side EtherNet/IP ForwardOpen connection-path parser. This allows a remtoe 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 and specifically linked to commit 76b95cf represents a critical security flaw located in the server-side parsing logic for EtherNet/IP ForwardOpen connection paths. This implementation error is classified as an out-of-bounds read, which falls under the Common Weakness Enumeration category CWE-125. The core technical issue arises when the application processes incoming network packets that contain malformed or excessively long connection-path data structures. Instead of performing rigorous bounds checking before accessing memory locations referenced by these paths, the parser proceeds to read from invalid memory addresses. This lack of input validation allows a remote attacker who can communicate with the OpENer service over the EtherNet/IP protocol to trigger this erroneous behavior without requiring any form of authentication or prior interaction beyond sending specific crafted network packets.
From an operational perspective, the immediate impact of exploiting this out-of-bounds read is a denial of service against the affected system. When the application attempts to access memory outside its allocated boundaries, it typically results in a segmentation fault or similar critical error that causes the process to crash abruptly. For industrial control systems and automation environments where OpENer serves as an open-source EtherNet/IP adapter implementation, such crashes can lead to significant downtime. The loss of connectivity between programmable logic controllers, human-machine interfaces, and other networked devices disrupts operational workflows and potentially compromises safety if critical monitoring or control functions are interrupted unexpectedly. This aligns with the ATT&CK technique T1499, specifically endpoint denial of service via application exhaustion or crash mechanisms, highlighting how a single vulnerability can degrade system availability in industrial settings.
Mitigation strategies for this vulnerability primarily involve updating to a patched version of OpENer where the connection-path parser has been hardened with proper bounds checking and input validation routines. Until an official patch is available, administrators should restrict network access to the EtherNet/IP service using firewall rules or VLAN segmentation to ensure that only trusted devices can send ForwardOpen requests. Additionally, deploying intrusion detection systems capable of identifying anomalous packet sizes or malformed protocol structures may help in detecting attempted exploitation before it triggers a crash. It is also advisable to review logging mechanisms to monitor for repeated connection attempts from unexpected sources, which could indicate reconnaissance activity preceding an exploit attempt.