CVE-2021-32926
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 · uneditedWhen an authenticated password change request takes place, this vulnerability could allow the attacker to intercept the message that includes the legitimate, new password hash and replace it with an illegitimate hash. The user would no longer be able to authenticate to the controller (Micro800: All versions, MicroLogix 1400: Version 21 and later) causing a denial-of-service condition
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 confidenceDuring an authenticated password change on Micro800 and MicroLogix 1400 controllers, an attacker with network positioning can intercept the message containing the new password hash and replace it with an arbitrary hash. This breaks the password change integrity, preventing legitimate users from authenticating and causing a denial-of-service condition.
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 dataall versions>= 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 controller model and firmware versionAccess the controller via RSLogix/MicroStudio or check the device web interface or connected HMI to determine if the device is a Micro800 or MicroLogix 1400 and note the exact firmware revision number.Affected if The device is a Micro800 (all versions) or MicroLogix 1400 with firmware version 21.0 or higher.
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Confirm password change is network-accessibleVerify whether the controller management interface (web server, RSLinx, or EtherNet/IP communication) is accessible from network segments beyond the trusted control system network. Check device network configuration and firewall rules.Affected if The password change interface is reachable from network segments outside the trusted control system, allowing an intercepting attacker to reach the device.
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Check for network exposure to interceptionReview network topology, switch port configurations, and ACLs to determine if traffic to/from the controller passes through any untrusted network segments or shared infrastructure where a man-in-the-middle attack could be performed.Affected if The controller network traffic can be intercepted by an attacker with positioning on the network path between the device and the administrative station initiating the password change.
If the device is a Micro800 (any version) or MicroLogix 1400 firmware >=21.0, and the password change interface is network-accessible without proper isolation, the environment is affected by this vulnerability.
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 dataApply vendor firmware updates when available; in the interim, implement network segmentation and restrict access to the device management interfaces to prevent interception attacks.
- Consultation6.0 h
- Implementation12.0 h
- Testing8.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-32926 — 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-2021-32926 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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- Version or environment caveats, and links to real fixes
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