CVE-2021-22681: Rockwell Multiple Products Insufficient Protected Credentials Vulnerability

Vulnerability summary

CVE-2021-22681 is a critical (CVSS 9.8) Insufficiently Protected Credentials vulnerability in Rockwell Multiple Products. It is known to be exploited: CISA lists it, first on 05-03-2026. EPSS estimates a 63.63% chance of exploitation in the next 30 days, higher than 99.2% of scored vulnerabilities.

Timeline

1. 03-03-2021
   PublishedVulnerability first disclosed.
2. 05-03-2026
   Added to CISA KEVRockwell Multiple Products Insufficient Protected Credentials Vulnerability
3. 06-03-2026
   Last modifiedVulnerability information updated.
4. 26-03-2026
   CISA remediation dueApply mitigations per vendor instructions.

Description

Rockwell Automation Studio 5000 Logix Designer Versions 21 and later, and RSLogix 5000 Versions 16 through 20 use a key to verify Logix controllers are communicating with Rockwell Automation CompactLogix 1768, 1769, 5370, 5380, 5480: ControlLogix 5550, 5560, 5570, 5580; DriveLogix 5560, 5730, 1794-L34; Compact GuardLogix 5370, 5380; GuardLogix 5570, 5580; SoftLogix 5800. Rockwell Automation Studio 5000 Logix Designer Versions 21 and later and RSLogix 5000: Versions 16 through 20 are vulnerable because an unauthenticated attacker could bypass this verification mechanism and authenticate with Rockwell Automation CompactLogix 1768, 1769, 5370, 5380, 5480: ControlLogix 5550, 5560, 5570, 5580; DriveLogix 5560, 5730, 1794-L34; Compact GuardLogix 5370, 5380; GuardLogix 5570, 5580; SoftLogix 5800.

• CWE-522Insufficiently Protected CredentialsThe product transmits or stores authentication credentials, but it uses an insecure method that is susceptible to unauthorized interception and/or retrieval.