CVE-2021-22681
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedRockwell 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceAuthentication bypass vulnerability in Rockwell Automation Studio 5000 Logix Designer and RSLogix 5000 where the key verification mechanism used to verify communications between engineering software and Logix controllers can be bypassed by an unauthenticated attacker, allowing unauthorized access to CompactLogix, ControlLogix, GuardLogix, DriveLogix, and SoftLogix controllers.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data>= 2.10>= 16, <= 20>= 21.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify installed Studio 5000 Logix Designer or RSLogix 5000 versionOpen the software and navigate to Help > About, or check Add/Remove Programs for the version numberAffected if Version is RSLogix 5000 between 16 and 20 inclusive, or Studio 5000 Logix Designer version 21.0 or higher, or FactoryTalk Services Platform >= 2.10
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Check for presence of affected Logix controllers on the networkReview network documentation or use PLC enumeration tools to identify CompactLogix, ControlLogix, GuardLogix, DriveLogix, or SoftLogix controllers connected to the engineering workstationAffected if Any of these controller types are present and connected to the vulnerable software
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Verify engineering workstation network exposureReview firewall rules and network segmentation to determine if the workstation running the affected software is directly accessible from untrusted networksAffected if The workstation has direct access from networks outside the control system DMZ or is exposed to the enterprise network
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Check FactoryTalk Services Platform version if deployedOpen FactoryTalk Administration Console or check installed programs for FactoryTalk Services Platform versionAffected if Version is 2.10 or higher
A user is affected if they have Studio 5000 Logix Designer >= 21.0, RSLogix 5000 versions 16-20, or FactoryTalk Services Platform >= 2.10 installed and these are used to communicate with CompactLogix, ControlLogix, GuardLogix, DriveLogix, or SoftLogix controllers, especially if the engineering workstation is network-exposed.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUpdate to patched versions when available from Rockwell Automation; implement network segmentation and restrict access to engineering workstations and controller networks; monitor for unauthorized authentication attempts.
- Consultation8.0 h
- Implementation16.0 h
- Testing12.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $11,200.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-22681 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-22681 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data