ICS impact; affects Rockwell automation software used in manufacturing; unauthenticated access to PLCs could disrupt operations.
CVE-2021-22681
Unauthenticated bypass allows unauthorized app to connect with Logix controllers.
Is CVE-2021-22681 being exploited?
Yes. CVE-2021-22681 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2021-22681?
CVE-2021-22681 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2021-22681?
Yes. A fix has been recorded for CVE-2021-22681. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2021-22681 affect?
CVE-2021-22681 affects Rockwell Studio 5000 Logix Designer (v21+), Rockwell RSLogix 5000 (v16–20), Logix controllers (ControlLogix, CompactLogix, GuardLogix, SoftLogix 5800), Rockwell design software ecosystem. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2021-22681?
Apply vendor mitigations; upgrade to patched versions
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated bypass enables unauthorized apps to connect to Logix controllers over the network, risking PLC manipulation.
Immediate action required
- affectedRSLogix 5000 Versions 16 through 20
- affectedStudio 5000 Logix Designer: Versions 21 and later
- affectedCompactLogix 1768, 1769, 5370, 5380, 5480
- affectedControlLogix 5550, 5560, 5570, 5580
- affectedDriveLogix 5560, 5730, 1794-L34
- affectedCompact GuardLogix 5370, 5380
- affectedGuardLogix 5570, 5580
- affectedSoftLogix 5800
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.