CVE-2021-22681
Rockwell Multiple Products Insufficient Protected Credentials Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 26 March 2026). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 63.63% probability · 99th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Listed 5 March 2026 · due 26 March 2026
- Weakness
- CWE-522
- Affected
- rockwellautomation/factorytalk services platform · rockwellautomation/rslogix 5000 · rockwellautomation/studio 5000 logix designer
- Source
- ics-cert@hq.dhs.gov
EPSS 63.6% since 30 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
CISA notes
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. 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
References
- https://us-cert.cisa.gov/ics/advisories/icsa-21-056-03Third Party Advisory, US Government Resource
- https://us-cert.cisa.gov/ics/advisories/icsa-21-056-03Third Party Advisory, US Government Resource
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22681US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.