CVE-2021-22681: Rockwell Automation Studio 5000 Exposes Verification Key, Enabling Unauthorized Logix Controller Access
CVE-2021-22681 affects Rockwell Automation's Studio 5000 Logix Designer, which stores a controller verification key without adequate protection. An attacker with network access can extract the key and use it to connect unauthorized applications directly to Logix PLCs, enabling ladder logic modification, configuration theft, or process disruption. CISA has added this vulnerability to its Known Exploited Vulnerabilities catalog with a federal patching deadline of March 26, 2026.