CVEs / CVE-2021-22681
CVE-2021-22681: Rockwell Multiple Products Insufficient Protected Credentials Vulnerability
- Known exploited in the CISA KEV catalog since 5 Mar 2026
- critical 9.8 CVSS 3.1 (NVD)
- EPSS 63.6% chance of exploitation in the next 30 days, higher than 99% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
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.
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 and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| n/a Rockwell Automation Studio 5000 Logix Designer, RSLogix 5000, Logix Controllers | RSLogix 5000 Versions 16 through 20 | — |
| n/a Rockwell Automation Studio 5000 Logix Designer, RSLogix 5000, Logix Controllers | Studio 5000 Logix Designer: Versions 21 and later | — |
| n/a Rockwell Automation Studio 5000 Logix Designer, RSLogix 5000, Logix Controllers | CompactLogix 1768, 1769, 5370, 5380, 5480 | — |
| n/a Rockwell Automation Studio 5000 Logix Designer, RSLogix 5000, Logix Controllers | ControlLogix 5550, 5560, 5570, 5580 | — |
| n/a Rockwell Automation Studio 5000 Logix Designer, RSLogix 5000, Logix Controllers | DriveLogix 5560, 5730, 1794-L34 | — |
| n/a Rockwell Automation Studio 5000 Logix Designer, RSLogix 5000, Logix Controllers | Compact GuardLogix 5370, 5380 | — |
| n/a Rockwell Automation Studio 5000 Logix Designer, RSLogix 5000, Logix Controllers | GuardLogix 5570, 5580 | — |
| n/a Rockwell Automation Studio 5000 Logix Designer, RSLogix 5000, Logix Controllers | SoftLogix 5800 | — |
Exploitation
| In CISA KEV since | 5 Mar 2026 |
|---|---|
| Due date for US federal agencies | 26 Mar 2026 |
| Used in ransomware campaigns | Unknown |
| 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. |
Severity
| CVSS 3.1 | 9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HScored by NVD |
|---|---|
| Weakness | CWE-522 |
References
- CVE-2021-22681 on NVD
- CVE-2021-22681 in the CISA KEV catalog
- https://support.rockwellautomation.com/app/answers/answer_view/a_id/1130301/~/cve-2021-22681%3A-authentication-bypass-vulnerability-found-in-logix-controllers- (cited by CISA)
- https://www.cisa.gov/news-events/ics-advisories/icsa-21-056-03 (cited by CISA)
- https://us-cert.cisa.gov/ics/advisories/icsa-21-056-03 Third Party Advisory, US Government Resource
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22681 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.