CVE-2021-21777: Opener Project Opener

Critical severity, CVSS 10.0. EPSS: 1.7% chance of exploitation in the next 30 days.

An information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer 2.3 and development commit 8c73bf3. A specially crafted network request can lead to an out-of-bounds read.

Affected products

• Opener Project Opener: version 2.3 only

Published 2021-06-17. Last modified 2026-06-17.