The vulnerability is an out‑of‑bounds read (CWE‑125) in the Connection Manager component of OpENer when it processes malformed ForwardOpen or LargeForwardOpen packets. A malicious actor can send a valid ENIP outer frame with a CIP ForwardOpen packet that does not contain enough data. The parser will read past the end of the supplied packet, potentially exposing data stored elsewhere in memory. The description does not indicate that the flaw causes crashes or memory corruption.

EIPStackGroup OpENer 2.3.0 (commit 76b95cf) is the only product listed as vulnerable. No other vendors or versions are reported to be affected.

An adversary can trigger the vulnerability remotely over the network without authentication. The EPSS score is reported as less than 1%, and the flaw is not included in the CISA KEV catalog, making the precise likelihood of exploitation unclear. With a CVSS score of 9.1, the severity is high, underscoring the importance of mitigating this vulnerability promptly. The remote trigger and lack of authentication gate mean that hosts exposed to untrusted networks face a moderate to high risk. If the server is behind a firewall or otherwise isolated, the threat is mitigated, but any exposed instance can be abused to read sensitive data from memory.