CVE-2021-22681

CRITICAL

9.8

CVSS Score

Published: March 3, 2021 at 05:59 PM UTC

Updated: June 17, 2026 at 03:37 AM UTC

21 products affected across 1 vendorFactoryTalk Services PlatformStudio 5000 Logix DesignerRslogix 5000

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Severity

CRITICAL9.8

Exploitation

CISA KEV

Exploit prediction

EPSS 64%

SSVC

Active

Actively Exploited

CISA Known Exploited Vulnerabilities (KEV) Catalog

EPSS Score63.6%

EPSS (Exploit Prediction Scoring System) estimates a 63.6% chance this CVE is exploited in the wild within the next 30 days — higher than 99% of all CVEs. It complements CVSS: a high EPSS on a mid-severity CVE can still be urgent.

Multiple Rockwell products contain an insufficient protected credentials vulnerability. Studio 5000 Logix Designer software may allow a key to be discovered. This key is used to verify Logix controllers are communicating with Rockwell Automation design software. If successfully exploited, this vulnerability could allow an unauthorized application to connect with Logix controllers. To leverage this vulnerability, an unauthorized user would require network access to the controller.

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.

Ransomware Use

Unknown

Added to KEV

Mar 5, 2026

Remediation Due

Mar 26, 2026

220 days overdue

Notes

https://support.rockwellautomation.com/app/answers/answer_view/a_id/1130301/~/cve-2021-22681%3A-authentication-bypass-vulnerability-found-in-logix-controllers-

https://www.cisa.gov/news-events/ics-advisories/icsa-21-056-03

https://nvd.nist.gov/vuln/detail/CVE-2021-22681

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

FactoryTalk Services Platform · Rockwell Automation

95%

v ≥ 2.10

rockwellautomation-compact-guardlogix-5370 (environment) · rockwellautomation-compact-guardlogix-5380 (environment) · rockwellautomation-compactlogix-1768 (environment) · rockwellautomation-compactlogix-1769 (environment) · rockwellautomation-compactlogix-5370 (environment) · rockwellautomation-compactlogix-5380 (environment) · rockwellautomation-compactlogix-5480 (environment) · rockwellautomation-controllogix-5550 (environment) · rockwellautomation-controllogix-5560 (environment) · rockwellautomation-controllogix-5570 (environment) · rockwellautomation-controllogix-5580 (environment) · rockwellautomation-drivelogix-1794-l34 (environment) · rockwellautomation-drivelogix-5560 (environment) · rockwellautomation-drivelogix-5730 (environment) · rockwellautomation-guardlogix-5570 (environment) · rockwellautomation-guardlogix-5580 (environment) · rockwellautomation-softlogix-5800 (environment)

Rslogix 5000 · Rockwell Automation

95%

v ≥ 21v ≤ 2016 ≤ v ≤ 20Compact GuardLogix 5370, 5380 CompactLogix 1768, 1769, 5370, 5380, 5480 ControlLogix 5550, 5560, 5570, 5580 DriveLogix 5560, 5730, 1794-L34 GuardLogix 5570, 5580 SoftLogix 5800

Studio 5000 Logix Designer · Rockwell Automation

95%

v ≥ 21v ≤ 20Compact GuardLogix 5370, 5380 CompactLogix 1768, 1769, 5370, 5380, 5480 ControlLogix 5550, 5560, 5570, 5580 DriveLogix 5560, 5730, 1794-L34 GuardLogix 5570, 5580 SoftLogix 5800

Logix Controllers · Rockwell Automation

60%

v ≥ 21v ≤ 20Compact GuardLogix 5370, 5380 CompactLogix 1768, 1769, 5370, 5380, 5480 ControlLogix 5550, 5560, 5570, 5580 DriveLogix 5560, 5730, 1794-L34 GuardLogix 5570, 5580 SoftLogix 5800

Compact GuardLogix® 5370 · Rockwell Automationdevice

80%

All versions