CISA KEV · Known exploitedCritical

CVE-2021-22681

Rockwell Multiple Products

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...

CVSS
9.8
EPSS
61.0%
99.1% percentile
CISA KEV
Listed
Published
2021.03.04
PRIORITY ASSESSMENT

Immediate review

CISA has listed this vulnerability in the Known Exploited Vulnerabilities catalog.

Known exploitationConfirmed by CISA KEV
Exploit probability61.0%
Technical severityCVSS 9.8

Vulnerability overview

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...

Affected product and versions

Product
Rockwell Multiple Products
Affected versions
RSLogix 5000 Versions 16 through 20, Studio 5000 Logix Designer: Versions 21 and later, CompactLogix 1768, 1769, 5370, 5380, 5480, ControlLogix 5550, 5560, 5570, 5580, DriveLogix 5560, 5730, 1794-L34, Compact GuardLogix 5370, GuardLogix 5570, SoftLogix 5800, >= 2.10, >= 16 <= 20, >= 21.0
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
CISA required action

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Due date: 2026.03.26
  1. 1
    Identify

    Confirm that Rockwell Multiple Products and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-522
KEV added
2026.03.05
Ransomware use
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